WORLD METEOROLOGICAL ORGANIZATION

WORLD WEATHER WATCH

NINETEENTH STATUS REPORT ON IMPLEMENTATION

1999

WMO-No. 894

Secretariat of the World Meteorological Organization - Geneva - Switzerland WORLD METEOROLOGICAL ORGANIZATION

WORLD WEATHER WATCH

NINETEENTH STATUS REPORT ON IMPLEMENTATION

1999

WMO-No.894

Secretariat of the World Meteorological Organization- Geneva- Switzerland © 1999, World Meteorological Organization ISBN 92- 63- 10894- 3

NOTE

The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the World Meteorological Organizati on concerning the legal status of any country, terri tory, city or area, of its authorities, or concern ing the delimitation of its frontiers or boundaries. FOREWORD

The World Weather Watch (WWW) Programme of the World Meteorological Organization (WMO) was adopted in 1963 by the Fourth World Meteorological Congress. Since then it has grown to be fundamental for all WMO and other related programmes as regards the provision of basic meteorological data and products, telecommunication services and the management thereof. In continuing to attribute the highest priority to the furtherance and implementation of WWW, Twelfth Congress in Resolution 2 urged all Members of the Organization to cooperate actively and enthusiastically in the implementation of the WWW. This publication is the 19th in a series of biannual reports on the status of implementation of WWW. It was mainly designed to inform the senior management of the national Meteorological and Hydrological Services (NMHSs), but also interested academia and the private sector of the operational status of WWW. It provides information concerning the structure, status and trends of the implementation, as well as performance of the core components of WWW, notably the Global Observing System (GOS), the Global Telecommunication System (GTS) and the Global Data-processing System (GDPS). In some parts this publication has been compacted from detailed information and reports made available by Members to the Commission for Basic Systems (CBS) and the working groups of the Regional Associations (RAs) dealing with www. I wish to take this opportunity to express my sincere appreciation to the Members of WMO for their continuing efforts toward the consolidated further development of WWW, as well as their collaboration in providing the information on which this report is based.

~- --- -···-----·~------G. 0. P. Obasi (Secretary-General)

CONTENTS

Page

Foreword ...... V

CHAPTER I-EXECUTIVE SUMMARY ...... 1-1 Introduction ...... 1-1 Global Observing System (GOS) ...... 1-1 Global Telecommunication System (GTS) ...... 1-2 Global Data-processing System (GDPS) ...... 1-2 World Weather Watch Data Management ...... 1-3

CHAPTER II- INTRODUCTION ...... Il-l Purpose and scope of the WWW programme ...... Il-l Components of the WWW system ...... Il-l Organization of WWW programmes ...... 11-1 Relationship of WWW with other programmes ...... II-2

CHAPTER Ill- THE GLOBAL OBSERVING SYSTEM ...... Ill-! Requirements for observational data ...... III-1 Implementation of the surface-based subsystem ...... 111-1 Upper-air stations ...... 111-2 Climatological observations ...... III-2 Marine meteorological observations ...... III-4 Aircraft meteorological observations ...... II!-6 Other observation stations/systems ...... III-6 The space-based subsystem ...... Ill-7 Multi-functional transport satellite ...... , ...... III-8

Quality of observational data ...... III-10 Upper-air data quality ...... III-11

Land-surface data quality ...... III-11

Marine surface data quality ...... III-11

CHAPTER IV- THE GLOBAL TELECOMMUNICATION SYSTEM ...... IV-I Data-communication techniques and procedures ...... IV-1 Radiofrequencies for meteorological activities ...... IV-2

Multi-point telecommunication services via satellite and radiobroadcasts ...... IV-2 IV CONTENTS

Page

MTNs ...... I.V-2 RMTNs ...... lV-3 Status of implementation and operati on of the GTS ...... IV-3

CHAPTER V-THE GLOBAL DATA-PROCESSING SYSTEM ...... V-1 RSMCs with geographical specialization ...... V-1 RSMCs wi th activity specialization V-8 Medium-range weather forecasting V-8 Tropical cyclone forecasting ...... V-8 Provision of transport model products for environmental emergency responses ...... V-8 NMCs and centres with similar functions ...... V-10 Verification of numerical weather prediction ...... V-10 Technical development at GDPS centres ...... V-10 LAMs ...... V-10 Long-range forecasts, climate diagnostics and predictions ...... V-12

CHAPTER VI - WORLD WEATHER WATCH DATA MANAGEMENT ...... VI-1 WMO distributed data bases ...... VI-1 Software exchange ...... VI-1 Data representation forms ...... VI-1 The year 2000 ·problem ...... VI- 1 Impact ofth e. Internet ...... VI-2

ANNEXES Annex 1- Summary of the results of the annual global· monitoring of the operation of the World Weather Watch (WWW) carried out from 1 to 15 October 1998 ...... AI-l Annex II- WWW Operational Information Service (OIS)...... AII-1 Annex Ill- Acronyms ...... - ...... AIH-l Annex IV - References ...... AIV-1 CHAPTER I EXECUTIVE SUMMARY

STATUS OF THE WORLD WEATHER WATCH

INTRODUCTION 7. One of the main factors affecting the global upper-air network in the last two years was the termina­ 1. The World Weather Watch (WWW) is an interna­ tion of the Omega radio navigation system, which 25 per tional cooperative programme that oversees the cent of the upper-air stations depended on for wind gathering and distribution of meteorological data and finding. Replacement of Omega by other systems, most­ products to World Meteorological Organization (WMO) ly Global Positioning System (GPS)-based systems, is Members. This Nineteenth Status Report on Implementation expected to be completed by mid-1999*. documents the progress and changes made in 1997 and 8. In order to meet the expanding need for climato­ 1998 within the various components of WWW. logical data, the Global Climate Observing System (GCOS) was established. Stations prepare monthly sum­ maries of surface and upper-air reports for the previous GLOBAL OBSERVING SYSTEM (GOS) month, using WMO code forms CLIMAT and CLIMAT TEMP, respectively. The number of CLIMAT reporting 2. GOS consists of facilities for making observations stations increased 37 per cent (to 2 499) in the last 10 on land and at sea, and from aircraft and satellite. years, while the number of CLIMAT TEMP stations 3. Each of the six Regional Associations (RAs) draws remained nearly constant, at about 520. up a regional network of observing stations, called a 9. A subset of the RBSN, the GCOS Upper-Air Regional Basic Synoptic Network (RBSN), to meet the Network (GUAN) was established in 1996 to meet GCOS collective needs of its Members. The total number of requirements for upper-air data. Results of-special mon­ RBSN surface stations reporting has not significantly itoring campaigns in 1997 showed that two thirds of changed since 1988 (currently 4 046 stations). About 74 GUAN stations were producing less than 75 per cent of per cent of these stations make the complete observing their required reports, and that 20 per cent of the sta­ program of at least eight observations per day (every tions exhibited unacceptably large errors. three hours). The number of reports actually received at 10. The GCOS Surface Network (GSN) was recently centres on the Global Telecommunication System (GTS) established to ensure a globally-consistent, high-quality varies regionally, from 50 per cent of those "required" in baseline network. This network consists of about 1 000 Region I, to 94 per cent in Region VI, with a global aver­ stations with a density of approximately one station per age of 72 per cent. There has been relatively little 250 000 square kilometres. Monitoring of the GSN was change in SYNOP (report of surface observation from a set to begin in 1999. land station) reporting in the last decade. 11. WMO relies on ships, moored and drifting buoys, 4. In addition to stations in the RBSNs, a large num­ and stationary platforms for synoptic and upper-air ber of supplementary stations have been established observations over the oceans. Currently, about 300 over the past 10 years to meet regional and national moored buoys and 600 fixed platforms serve as auto­ needs. Most of these stations are automated and record matic marine stations, though only about 120 of these observations hourly. transmit data globally over the GTS. During the past 10 5. About 69 to 70 per cent of RBSN upper-air stations years, the number of air-pressure reports from drifting (radiosonde and radiowind) make two observations per buoys grew four-fold, to 120 000 per month, and the day, a decrease from 72 to 73 per cent 10 years ago. A observation quality increased substantially. lower percentage of Southern Hemisphere stations 12. The operational drifting buoy program comprised makes two observations per day as compared with the about 1 000 drifting buoys in October 1998, with Northern Hemisphere. more than 600 transmitting 6 600 reports on the GTS 6. The results of a three-month monitoring period of during a 24-hour period. Ships participating in the RBSN upper-level temperature, humidity and wind from WMO Voluntary Observing Ship (VOS) programme land station (TEMP) reports show 210 "silent" stations make SHIP (report of surface observation from a sea sta­ in 1998, and a persistence of data-sparse areas over some tion) reports. A typical distribution of SHIP and buoy parts of Africa, Asia, northern South America and the reports in 1998 showed data-void regions in the oceans. No reports were received from almost one-quar­ Southern Hemisphere. ter of the TEMP stations. Nearly half of the expected TEMP reports were not received during the global mon­ The higher cost of the GPS-based radiosondes is one reason for itoring period of 1 to 15 October 1998. the decrease from two to one upper-air observation per day. 1-2 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENTATION

13. The number of SHIP reports received at the Main Data Distribution (MDD) operated via the European Telecommunication Network (MTN) has continued to Organization for the Exploitation of Meteorological increase since 1992, despite a significant drop in the Satellites (EUMETSAT) series of geostationary satellites actual number of participating ships in 1992. (METEOSAT) remain essential components of the GTS in Furthermore, the quality of observations (air pressure RA I, and offer the potential for improving data collec­ and surface winds) has improved. tion in the future. Observational data collection in RA 11 14. Conventional aircraft reporting has increasingly is generally satisfactory, except in a few countries. A been supplemented or replaced by automated reporting. pilot project is being developed for improving the dis­ Since 1992, the amount of automated aircraft-to-satellite semination of data via satellite facilities operated by the data acquisition and relay (ASDAR) and Aircraft United Kingdom. In RA Ill, the three RTHs are connect­ Communication Addressing and Reporting System ed via medium-speed circuits, but most National (ACARS) data, collectively known as aircraft meteo­ Meteorological Centres (NMCs) are connected via low­ rology data acquisition and relay (AMDAR), has speed circuits that cannot meet current requirements. In multiplied by a factor of nearly 15. Data coverage was RA IV, the RMTN mainly consists of a two-way satellite­ more extensive in 1998 than in 1996, especially over based network implemented by the International South America and Africa, thus partly compensating for Satellite Communication System {ISCS) operated by the the relatively lower coverage by RBSN upper-air stations United States of America. This system is fully operational in those regions. in all countries concerned except Haiti. The satellite­ 15. The number of satellite receivers operated by based network is complemented by some medium to WMO Members has increased since 1990, with a total of high-speed circuits. In RA V, links to small nations in the about 1 200 registered satellite receivers operating by the Pacific are extremely difficult to operate in a cost-effec­ end of 1998. The overall percentage of implementation tive manner. Various alternative communication was 79 per cent, an increase from 70 per cent in 1997. solutions, as well as the Internet, are planned for The WMO goal for implementation of satellite receivers, improving the RMTN there. The major effort in RA VI which requires each WMO Member to be equipped with has been establishing the Regional Meteorological Data at least one geostationary and one polar-orbiting satel­ Communication Network (RMDCN). The RMDCN will lite receiver, has nearly been attained. meet RA VI GTS requirements as well as data exchange requirements between the European Centre for Medium­ GLOBAL TELECOMMUNICATION SYSTEM (GTS) Range Weather Forecasts (ECMWF) and its member states and cooperating states. It will replace point-to­ 16. The GTS is comprised of the MTN, Regional point circuits. Meteorological Telecommunication Networks (RMTNs) 19. Satellite-based multipoint telecommunication sys­ and National Meteorological Telecommunication tems are an essential component of the GTS, and each Networks (NMTNs). The MTN is the backbone of the WMO region is completely covered by at least one satel­ GTS, connecting regions via major Regional Telecom­ lite distribution system. These systems effectively munication Hubs (RTHs). The RMTNs connect WWW complement point-to-point circuits, particularly in the centres within a Region, and the NMTNs connect mete­ delivery of processed meteorological information to orological stations or centres of a particular country. NMCs. 17. All 23 MTN circuits are in operation and all MTN 20. High frequency (HF) broadcasts have high recur­ centres are automated. There has been noteworthy rent operational costs and limited efficiency; improvement in circuit speed, as most circuits are at consequently, several Members have discontinued oper­ medium and some at high speed. Eight out of 23 circuits ating them. In some instances, they have been replaced use digital technology at speeds from 64 to 128 kbits/s. by satellite distribution systems. The other MTN circuits operate at rates greater than 4.8 21. Radiofrequency allocations to radiosondes and kbits/s, except for one telegraphic circuit. All but one of meteorological satellites face a continuing threat by the the MTN circuits currently use X.25 protocol, which has telecommunications industry. At the World Radiocom­ been the GTS standard for several years. Subsequently, munication Conference (WRC) in 1997, coordination the Commission for Basic Systems (CBS) has decided between national Meteorological Services (NMSs) and that the Transmission Control Protocol/lnternet the WMO resulted in measures to safeguard the radiofre­ Protocol {TCP /lP) should replace X.25 technology in the quencies allotted to meteorology. However, the threat to future, and is already in use on several bilateral links. these bands will continue at least until the next WRC in 18. Significant progress has been made in implement­ 2000. ing RMTNs and connecting them to the MTN, but serious shortcomings still exist in some geographic GLOBAL DATA·PROCESSING SYSTEM (GDPS) areas. In RA I, significant improvements have been made in the implementation of RMTN point-to-point circuits. 22. The GDPS is a worldwide programme for the Still, the collection of observational data remained analysis and coordinated array of meteorological centres unsatisfactory (less than 50 per cent) due to national dif­ for the provision of forecast products and other envi­ ficulties in installing and maintaining equipment. The ronmental information. It generates nearly all the Data Collection System (DCS) and the Meteorological Numerical Weather Prediction (NWP) products required EXECUTIVE SUMMARY 1-3 by Members. The GDPS is made up of World has continued among nine GDPS centres. A small but Meteorological Centres (WMCs), Regional Specialized steady improvement in forecasting 500-hPa height over Meteorological Centres (RSMCs), and NMCs. Asia, Europe and North America was observed up until 23. Most RSMC operations in RAs 11, Jll, IV and V have 1996. This positive trend stopped in 1997, when nearly shown sustained improvement by enhancing their fore­ all the models performed less well than the previous cast systems and computer facilities. In RA I, some year, except possibly over North America. Similarly, fore­ RSMCs still need to upgrade their data-processing equip­ casting winds over the tropics also showed no ment to perform all the functions required. Computer improvement in 1997. capabilities are well developed at many NMCs, particu­ 28. Several advanced GDPS centres are actively larly those in RAs 11 and VI. While there is still a lack of engaged in climate diagnosis activities at global, regional real-time data-processing and NWP capabilities in the and national levels. Only alimited number of centres NMCs of many developing countries, satellite-based dis­ take part in extended-range forecasting and seasonal semination systems enable NMCs to receive products predictions. from WMCs and RSMCs. Many NMCs have access to selected GDPS products on the Internet. WORLD WEATHER WATCH DATA MANAGEMENT 24. The use of massive parallel processor technology has allowed several advanced GDPS centres to put data 29. WMO Distributed Databases (DDBs) provide data assimilation systems with three- or even four-Dimension and information needed by WMO and related interna­ Variational Analysis (4DVA) into operation. These tional programmes, but not routinely exchanged on the schemes improve the initial fields required for NWP. GTS. DDBs have been implemented by many centres Physical parameterization schemes (e.g., for convection, and are used by many more. Members using these serv­ cloud and radiation) are constantly being improved, ices report they have found that the offered data and which leads to better very-short and short-range predic­ products have made an important contribution to their tions, especially over the tropics. operations. As a contribution to the WMO DDBs, the 25. Fifty centres run Limited Area Models (LAM), and Secretariat has made available from the WMO Internet 18 centres run mesoscale models, a substantial increase server the information contained in Weather Reporting over the last decade. Furthermore, global models (WMO-No. 9), Volumes A, C and D and in the Interna­ increased while hemispheric models decreased in number. tional list of selected, supplementary and auxiliary ships 26. Steady progress has been made in RSMC forecasts (WMO-No. 47) and contents of the BUFR code tables. of tropical cyclone tracks. Forecast errors at 12 and 24 30. Many NMHSs have implemented connections to hours were slightly lower in the 1997-98 season than in the Internet over the past few years. Based on a survey the 1996-1997 season. Most RSMCs apply statistical on connectivity conducted in late 1998, 137 NMHSs models to supplement deterministic numerical models. (95 per cent of respondents) have connections to the 27. Monthly exchange of forecast verification scores Internet, and 68 operate Web servers.

CHAPTERII INTRODUCTION

PURPOSE AND SCOPE OF THE WWW (b) GTS, composed of an increasingly automated PROGRAMME network of telecommunication facilities for the rapid, reliable collection and distribution 1. Meteorological services are required for the safety of observational data and processed information; of life and property, the protection of the environment, and and for the efficiency and economy of a wide range of (c) GDPS, consisting of World, Regional/Specialized weather-sensitive activities. Central to the provision of and National Meteorological Centres to provide these services is the receipt by NMCs of observational processed data, analyses and forecast products. data, analyses and forecasts. WWW is the international 4. Implementation and integration of the three core cooperative programme which arranges for the gathering elements are supported through the: and distribution in real-time on a worldwide scale of (a) WWW Data Management (WDM), which address­ meteorological information required by individual es standards and practices for the efficient Members, by other WMO programmes and relevant pro­ handling and flow of data and products within grammes of other international organizations. The full the WWW system; and description of the WWW Programme including the (b) WWW System Support Activities (SSA), which implementation goals are contained in WMO Long-term provide guidance, assistance and training to those Plan: Overall policy and strategy 1996--2005-Fourth WMO involved related to the planning, development Long-term Plan, Part I (WMO-No. 830) and the World and operation of WWW. Weather Watch Programme 1996-2005: Fourth WMO Long­ term Plan, Part II: Volume 1 (WMO/TD-No. 700). ORGANIZATION OF WWW PROGRAMMES 2. The overall objectives of WWW are: (a) To maintain an effective worldwide integrated sys­ 5. The WWW core elements are managed through tem for the collection, processing and rapid quasi-independent programmes, each supported by a exchange of meteorological and related environ­ corresponding organizational unit in the WMO mental data, analyses and forecasts; Secretariat. The SSA are carried out as integral parts of (b) To make available, in real-time and non-real-time, as the individual core programmes. The approved opera­ appropliate, observational data, analyses, forecasts tional procedures and practices of WWW are given in and other products to meet the needs of all Members, the regularly updated Manual on the Global Data-process­ of other WMO Programmes and of relevant pro­ ing System (WMO-No. 485), Manual on the Global grammes of other international organizations; Observing System (WMO-No. 544), Manual on the Global (c) To arrange for the introduction of standard meth­ Telecommunication System (WMO-No. 386), Manual on ods and technology which enable Members to Codes (WMO-No. 306), and the associated Guides make best use of the WWW system and ensure an (Annex II). adequate level of services and also the compatibil­ 6. In addition to the core element and support func­ ity of systems for cooperation with agencies tion programmes, WWW incorporates five other outside WMO; programmes that complement and enhance the WWW (d) To provide the basic infrastructure for GCOS and core elements in important specific areas: other WMO and international programmes for cli­ (a) Instruments and Methods of Observation mate monitoring and studying of climate issues. Programme (!MOP) aimed mainly at improving both the accuracy and homogeneity of observa­ COMPONENTS OF THE WWW SYSTEM tional data; (b) WMO Satellite Activities, which define environ­ 3. WWW operates at global, regional and national mental satellite data requirements and services levels. It involves the design, implementation and fur­ and strengthen Members' capabilities to receive ther development of three closely linked and and effectively use satellite data; increasingly integrated core elements: (c) Tropical Cyclone Programme (TCP) designed to (a) GOS, consisting of facilities and arrangements for assist NMSs in minimizing loss of life and proper­ making observations at stations on land and at ty damage caused by tropical cyclones and

sea 1 and from aircraft 1 environmental observation associated phenomena; satellites and other platforms, the system is (d) Emergency Response Activities which assist NMSs designed to provide observational data for use in to respond effectively in case of major nuclear both operational and research work; accidents; and 11-2 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENTATION

(e) WMO Antarctic Activities aimed at promoting and range of WMO programmes and related activities of coordinating the implementation and operation international organizations. Within WMO, these of the core elements of the WWW in the include TCP, the Marine Meteorology and Associated Antarctic. Oceanographic Activities Programme (MMAOAP), the 7. The WMO bodies primarily concerned with Public Weather Services (PWS) programme, Aeronautical WWW are CBS and the RAs. CBS is responsible for tech­ Meteorology, as well as the World Climate Programme nical matters relating to worldwide cooperation in the (WCP) and the Integrated Global Ocean Services System planning, implementation, operation and further devel­ (IGOSS). The WWW is envisaged to implement and opment of the WWW system, and has established operate the basic infrastructure for GCOS and, to some working groups that deal with the core WWW elements, extent, for the Global Terrestrial Observing System WDM and the WMO Satellite Activities. At the regional (GTOS). Of particular importance is the coordination of level the working groups on the regional aspects of the plans and activities between the WWW and interna­ WWW assist the RAs in coordinating the implementa­ tional organizations, notably the Food and Agriculture tionofWWW. Organization of the United Nations (FAO), International Atomic Energy Agency (!AEA), International Civil RELATIONSHIP OF WWW WITH OTHER Aviation Organization (ICAO), Intergovernmental PROGRAMMES Oceanographic Commission (IOC), International Telecommunication Union (!TU), United Nations 8. WWW provides both the common infrastructure Environment Programme (UNEP) and World Health and the meteorological database to support a broad Organization (WHO). CHAPTER III THE GLOBAL OBSERVING SYSTEM

REQUIREMENTS FOR OBSERVATIONAL DATA services. Each WMO RA draws up an RBSN to meet the collective needs of its Members. Together, these region­ 1. Although requirements are dictated to a large al networks form the global network. Generally, surface degree by the needs of numerical techniques, GOS also synoptic stations are expected to report every six hours has the responsibility of meeting the needs of WMO for global exchange and every three hours for regional programmes dealing with climate change, aviation and exchange, while upper-air stations are required to report agricultural forecasts and environmental quality moni­ at least twice per day. The details of all stations operated toring. The formulation of data requirements is an by Members is given in Weather Reporting (WMO-No. 9, evolving process based on experience with observing Volume A) systems and improvements in data assimilation tech­ niques. The process balances user demands with the IMPLEMENTATION OF THE SURFACE-BASED technical feasibility of data resolution. The require­ SUBSYSTEM ments for observational data are given in the Manual on the Global Data-processing System (WMO-No 485). Surface synoptic 2. The frequency and density of observations needed depend on the scale of the meteorological phenomena 4. The status of implementation of RBSN surface sta­ being analyzed and forecast - small scale, mesoscale, tions as of 1 October 1998, according to information large scale, or planetary scale. Short-range weather fore­ provided by Members, is presented in Table 1. The sub­ casts require more frequent observations from a denser stantial decrease in comparison with 1996 in the network over a limited area in order to detect small-scale number of surface stations included in the RBSN for phenomena and their development. As the length of the Region IV is the result of a rationalization and redesign forecast period increases so does the area over which of the network made at the twelfth session of RA IV in observations are required. May 1997. Although there have been small changes in 3. The WMO requirements for synoptic observation­ the level of implementation from Region to Region, the al data are generally divided into three categories - overall status is much the same as it has been for at least global, regional and national. The first two data types the last 10 years, as can be seen from the corresponding are mainly used to define the initial conditions of glob­ figures for 1988. al weather prediction models. Individual countries use 5. The 1998 Annual Global Monitoring of the national data as supplementary observations for now­ Implementation of the WWW reports the number of casting, severe weather warnings, and other specialized SYNOP reports actually received at centres on the GTS.

Table 1 Surface Synoptic Stations in the RBSN as of 1 October 1998 compared to those in 1996 and 1988. The numbers of stations expected to report every three hours, every six hours, and less frequently are shown. The total number of surface stations in the RBSN as committed to by Members in Weather Reporting (WMO-No. 9, Volume A) is shown under 11 Required ,, .

WMO Regions Required RBSN Making the complete Making observations Making some Stations not yet observing programme, at the main hours obse111ations daily established or otherwise at least 8 observations (0000, 0600, 1200 non-operational per day (0000, 0300, and 1800 UTC) 0600, 0900, 1200, 1500, 1800 and 2.100 UTC) Number Number % Number % Number % Number % 1996 1998 1996 1998 1998 1996 1998 1998 1996 1998 1998 1996 1998 1998 Region I 621 621 353 352 57% 38 38 6% 201 200 32Wo 29 31 5% Region II 1194 1195 I 092 I 098 92% 20 22 2% 58 58 5% 24 17 1% Region III 438 467 171 165 35% 0 5 1% 242 266 57% 25 31 7% Region IV 593 539 432 382 71% 41 27 5% 102 96 18% 19 34 6% Region V 406 410 225 254 62% 81 69 17% 83 69 17% 17 18 4% Region VI 682 726 645 678 93% 9 12 2% 21 20 3% 7 16 2% Antarctic 68 88 SI 76 86% 9 7 8% I I 1% 7 4 5% - GLOBAL 1998 4002 4046 2 969 3005 740Jo 198 180 4% 708 710 18% 128 151 4% G/oba/1988 4 040 3 042 75% 238 6% 612 15% 148- 4% 111-2 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENTATION

Highlights of that report are in Annex I. Figure 1 of the persistence of data-sparse areas over some parts of Africa, Annex shows that the percentage of reports received of Asia, South America and the oceans. those required by the RBSN in 1998 ranges from 50 per 9. One of the main factors affecting the global upper­ cent in Region I to 94 per cent in Region VI, with a glob­ . air network in the last two years was the termination of al average of 72 per cent. the Omega radionavigation system on which 252, or 25 6. In addition to stations in the RBSNs, a large number per cent, of the upper-air stations of the global network of supplementary stations have been established to meet were dependent for wind-finding. The Omega system regional and national needs. Some of these are automatic terminated its operation on 30 September 1997. By that stations, whose numbers are steadily increasing and have time, 166 of 192 operational stations had been convert­ now reached about 1 000. As shown in Table 2, there has ed to alternative wind finding systems (GPS-, been a steady increase in the total number of stations Long-range Navigation System (LORAN)-C, very-low fre­ established to meet global, regional and national require­ quency (VLF)-based or radiotheodolites). By December ments since 1988. Most of the new stations record hourly. 1998, Omega-based equipment had been replaced by There has been an increase of 8 to 11 per cent over the last alternative systems at all but 12 stations (Figure 4.) 10 years in the observations made at the four main hours, 10. A technical conference on Integrated Upper-air and a 22 per cent increase in the number of stations mak­ Observing under the auspices of CBS was held in ing hourly observations. Figure 1 below shows the changes Karlsruhe, from 28 to 29 September 1998. CBS agreed on over the period 1991 to 1998 in the number of surface sta­ recommendations on a strategy for the development tions Region by Region (with an indication of those and implementation of an integrated upper-air observ­ individual countries where there have been changes of 10 ing system. The strategy should consider proven or more). Many Automatic Weather Stations (AWSs) were technology and techniques, implications of recent installed in 1996. Most new stations are automatic and advances, and opportunities presented by emerging most of these report hourly. technology. The new composite system must utilize a range of mutually complementary technologies. Data­ UPPER-AIR STATIONS sparse areas should be targeted for coverage by new additional observing systems. As the needs for upper-air 7. Some 90 per cent of all existing upper-air stations data for climate research and numerical prediction con­ are included in the RBSNs. Table 3 shows the status of tinue to evolve, the effort to improve the integrated implementation of all RBSN upper-air stations in 1998 upper-air observing system should be coordinated with comparable figures for 1996. This comparison between WWW and GCOS. shows that even during the two-year period the number of fully operational stations decreased. Radiowind CLIMATOLOGICAL OBSERVATIONS stations dropped from 692 to 666. A reduction in the number of stations proposed for making two 11. The World Climate Programme (WCP) requires an observations per day occurred during the past 10 years, average coverage of 10 surface reporting stations per from 642 to 605 for radiosonde and from 720 to 666 for 250 000 square kilometers. Stations preparing monthly radiowind. (See figures for 1988 in Table 3). More summaries of surface and upper-air reports for the previ­ important is the geographic distribution. The Southern ous month, using the WMO code forms CLIMAT Hemisphere has lower percentages of stations proposed and CLIMAT TEMP, are indicated in Weather Reporting for making two observations a day than does the (WMO-No. 9). Resulting from the establishment of Northern Hemisphere. GCOS, the number of CLIMAT reporting stations has 8. The results of monitoring RBSN upper-air stations risen from 1 830 stations in 1988 to 2 499 stations in over a three-month period in 1992 and 1998 are shown 1998- an increase of 37 per cent (Table 2). The number in Figure 2 and Figure 3. These figures show an increase of CLIMAT TEMP stations has remained consistently at in the number of "silent" stations and show a around 520 for the past 10 years.

Table 2 All Surface Synoptic Stations counted for the period 1988 to 1998. The percentage change for the last decade is indicated as well as the numbers of stations making hourly and CLIMAT observations. Year Total number of stations Making observations at Climate reporting 0000 UTC 0600 UTC 1200 UTC 1800 UTC Hourly 1988 9 525 6 958 7 390 7 904 7 255 3 849 1 830 1990 9 649 7 016 7 483 7 499 7 323 3 965 2 247 1992 9 762 7 168 7 597 8 065 7 420 4 162 2 264 1994 9 950 7 314 7 786 8 313 7 634 4 449 2 310 1996 10 106 7 469 7 898 8 460 7 776 4 585 2 528 1998 10 214 7 697 8 017 8 595 7 926 4 712 2 499 - Increase since 1988 7% 11 o/o 8% 9% 9% 22% 37% THE GLOBAL OBSERVING SYSTEM III-3

•o

160'W140'W120'W 100'W 80'W 60'W 40'W 20'W 0' ZO'E 40'E 60'E BO'E 100'E 120'E Hll't 160'E 180 Figure I -The change in the number of all surface synoptic stations in the period 1991 to 1998 for all WMO Regions. Countries with changes greater than 10 are also shown.

Thble 3 Status of implementation of RBSN upper-air stations. (as all October 1998)

WMO Type of Requested in Making observations at Making one observation Stations not yet established or Regions observation the RBSN 0000 and 1200 UTC per day otherwise non·operational Number Number % Number % Number o/o 1996 1998 1996 1998 1998 1996 1998 1998 1996 1998 1998 Region I Radiosonde 101 101 32 24 24% 39 44 44% 30 33 33% Radlowind 128 128 49 37 29% 42 48 38% 37 43 34% Region 11 Radiosonde 326 326 264 266 82% 40 40 12% 22 20 6% Radiowind 336 336 269 271 81% 38 35 10% 29 30 9% Region III Radiosonde 52 56 14 16 29% 28 25 45% 10 15 27% Radiowind 52 56 14 16 29% 28 25 45% 10 15 27% Region IV Radiosonde ISO 142 131 123 87% 11 11 8% 8 8 6% Radiowlnd !51 143 131 123 86% 11 11 8% 9 9 6% Region V Radiosonde 96 97 29 41 42% 54 39 40% 13 17 18% Radiowind 129 130 87 82 63% 26 27 21% 16 21 16% Region VI Radiosonde 149 143 134 127 89% 6 12 8% 8 4 3% Radiowind ISO 143 134 129 90% 6 11 8% 9 3 2% Antarctic Radiosonde 14 14 6 8 57% 7 5 36% I I 7% Radiowind 14 14 7 8 57% 6 5 36% I 1 7% GLOBAL Radiosonde 888 879 610 605 69% 185 176 20% 92 98 11% 1998 Radiowind 960 950 692 666 70% !57 162 17% 111 122 13% Global Radiosonde 855 642 72% 166 19% 87 10% 1988 Radiowind 988 720 73% 147 15% 121 12%

12. GUAN, comprising 148 stations selected from the show that about two thirds of the stations were producing RBSNs, was established in 1996 to meet GCOS requirements less than 75 per cent of the required reports. Furthermore, an for upper-air data. According to the ECMWF Data analysis of the July-December 1997 monitoring period Monitoring Report for GUAN stations, which covered the revealed that 20 per cent of the stations exhibited either period January to June 1998, 17 upper-air stations or 11 per unacceptably large random variations or biases in measured cent of the overall number of GUAN stations, were consid­ parameters (see Report of the Adequacy of the Global ered "silent" stations (i.e. non-operational). Results of Climate Observing Systems). A GSN comprising about I 000 monitoring during a three-month period in 1997 (FigureS) selected surface stations was recently established with a 111-4 WORLD WEATHER WATCH -NINETEENTH STATUS REPORT ON IMPLEMENTATION

0

' V ·. ,0

Percentage of expected reports based on one sounding per day • >89% (465) 0 between 49 and 90% (206) 0 <50% (89) V silent sat!ons (213)

Figure 2- 1992 availability of upper-air data from RBSN stations shown as percentage of expected reports based on one sounding per day from July to September 1992. (Source: ECMWF)

Percentage of expected reports based on one sounding per day • >89% (469) 0 between 49 and 90% (169) 0 <50% (78) v silent satlons (201)

Figure 3- 1998 availability of upper-air data from RBSN stations shown as a percentage of expected reports based on one sounding per day from July to September 1998. (Source: ECMWF) density of approximately one station per 250 000 square upperMair observations over ocean areas. Observations kilometres, to monitor daily global and large-scale climate from ships adequately cover the major shipping lanes. variability. Monitoring of the operation of the GSN was to Moored and drifting buoys play a very important role in begin in 1999. providing observations from the large data-void ocean areas. MARINE METEOROLOGICAL OBSERVATIONS 14. Data-void areas are particularly noticeable in the Southern Hemisphere. The development of the WMO VOS 13. WMO relies on ships, moored and drifting buoys programme as shown in Table 4 indicates that there was a and stationary platforms for synoptic surface and very significant drop in the number of participating ships THE GLOBAL OBSERVING SYSTEM Ill-S

40-N

20'N

•o •o

'··.·'.

Figure 4 -Map showing locations from which wind observations had not been received following the cessation of the Omega system as of December 1998. (Source: ECMWF)

... @ . ..

• 75 to 100%Wind operational data~~~~~:;;;~~~~~~~~~~~~~~~~~~~~~~ T SO to 75% operational ® 25 to 50% operational 0 1 to 25% operational *Silent stations Figure 5- GCOS Wind data availability from the GUAN network during the monitoring period 1 July to 30 September 1997. (Source: ECMWF) between 1992 and 1994. This drop was almost entirely a 600 of them transmitting about 6 600 BUOY reports on result of some 600 fewer ships being registered under the the GTS during a 24-hour period. During the past 10 years Russian Federation than there were under the "former the number of air pressure reports from drifting buoys has Soviet Union". None of the Newly Independent States had increased from approximately 30 000 to 120 000 per reported their registrations. Nevertheless, the number of month. The collection of buoy data via satellite is carried SHIP reports being received at MTN centres has increased out mostly through the ARGOS System, a cooperative substantially and the quality of the observations, i.e. air undertaking between the centre nationale d'etudes spa­ pressure and surface winds, has improved (see paragraph tiales (CNES) of France, and the National Oceanic and 26), resulting in a large increase in the usable ship obser­ Atmospheric Administration (NOAA) of the United States vations worldwide. of America. 15. In October 1998, the operational drifting buoy pro­ 16. Automated marine stations on moored buoys and gramme comprised about I 000 drifting buoys, more than fixed platforms supplement the GOS to an increasing 111-6 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENTATION

Table 4 Number of WMO VOS stations from 1988 to 1998. The totals include the auxiliary ships, but it should be noted that they are not generally recruited on a permanent basis. Only about 40 per cent of the ships are actually at sea at any one time, and some of these may be operating in coastal waters, or may have difficulty in making observa tions or in passing them through coastal radio stations to centres on the GTS.

Type of observing ship Number of sl1ips recn1ited as of 1 January 1988 1990 1992 1994 1996 1998 Selected 4 438 4 642 4 608 4 092 4 150 4 158 Supplementary 1420 1 402 1 332 1 386 1 327 1 289 Auxiliary 1 344 1420 1 422 1 197 1 270 1 291 TOTAL 7 202 7 464 7 362 6 675 6 747 6 738 Average total number of N/A N/A 3 000 3 200 5 000 5 500 SHIP reports received at MTN centres per day extent. In addition to meteorological parameters, these these provide cruise level and ascent/descent meteoro­ stations provide oceanographic and other environmen­ logical data. ASDAR units provide about 1 400 reports tal data including wave h eight and direction, sea per day. Aircraft reports in ACARS code received at temperatures, water and air pollution data, and surface ECMWF for a random day are shown in Figure 6. These and underwater currents. The most recent information figures show that the data coverage from aircraft reports indicates that about 300 moored buoys and 600 fixed is very extensive in data-saturated areas such as platforms serve as automatic marine stations, although Europe and North America. As observations increase, only around 120 of these systems have their data trans­ more coverage can be expected in areas where there is a mitted globally over the GTS. relatively lower percentage implementation of the upper-air RBSN. AIRCRAFT METEOROLOGICAL OBSERVATIONS OTHER OBSERVATION STATIONS/SYSTEMS 17. Conventional aircraft reporting is increasingly supplemented by automated reporting. Automated 18. Observations from weather radar stations constitute reporting of meteorological data from aircraft is cost­ on e of the best mean s of studying small-scale and effective accurate and timely. The reports are used to mesoscale cloud precipitation systems. They are essential improve operatiqnal forecasts and to monitor issued for the effective and reliable d etection, tracking and forecasts and provide valuable input data for NWP. They forecasting/ warning of dangerous weather phenomena are also vital for the issuance of warnings to aircraft. such as tropical cyclones and tornadoes. In some Since 1992, the number of automated ASDAR and countries, systems combining the output of radar ACARS data, collectively known as AMDAR, h as networks and the information received from geostationary increased by a factor of nearly 15. Currently, 20 ASDAR meteorological satellites are in operational use, or are at an units are flown by six commercial airlines and 16 of advanced stage of development. The total number of such

figure 6 - Availability of ACARS data for a random time and date. There were 13 300 observations (3 912 AIREP, 3 299 A!v!DAR and 6 089 ACARS) at 1200 UTC on 14 September 1998. (Source: ECMWF) THE GLOBAL OBSERVING SYSTEM 111-7 combined systems is now more than 600. In addition, 20 MULTI-FUNCTIONAL TRANSPORT SATELLITE Members have indicated that they are operating Spherics Detection Systems for the detection and location of 21. Both polar-orbiting and geostationary satellites lightning flashes. provide visible and infrared cloud images. Geostationary 19. GOS also comprises stations intended for purposes satellites also provide water vapor images and indications such as the Global Atmospheric Watch (GAW), radiation of wind structure. The latter are of particular value in the measurements, meteorological rocket soundings, tropics. Polar-orbiting satellites are equipped with vertical climatological and agricultural meteorological profile radiometers for temperature and humidity observations, and radioactivity measurements. Because soundings. Both types of satellite operate data collection these stations mainly provide specialized information for and dissemination services. Figure 7 indicates the total WMO programmes outside WWW, details are not number of satellite receivers in each WMO Region from included here. 1990 through 1998. In general, the total number of receivers continues to increase. Figure 8 indicates the THE SPACE-BASED SUBSYSTEM percentage of implementation for satellite receivers. It should be noted that the goals for the percentage of 20. Environmental observation satellites constitute the implementation for WMO Members is 100 per cent for space-based subsystem of GOS, whose major goal is to polar-orbiting satellite data receivers (either automatic augment the information provided by the surface-based picture transmission (APT) or high-resolution picture subsystem in order to complete the global coverage. At transmission (HRPT)) and 100 per cent for geostationary the end of 1998, the satellite network included six satellite data receivers (either weather facsimile (WEFAX) operational near polar-orbiting satellites (including or high resolution (HR)). This means that each WMO NOAA, METEOR, and Defense Meteorological Satellite Member should be equipped with at least one polar­ Programme (DMSP) satellites) and five operational orbiting satellite data receiver and one geostationary Geostationary Environmental Observation Satellites. The satellite data receiver. The apparent decrease in current and future status of polar-orbiting and geosta­ Region V is due to an increase in the number of WMO tionary satellites is shown in Table 5. Members in the region and not a decrease in the number

Table 5 Satellites in orbit as of July 1998 coordinated with the Coordination Gronp for Meteorological Satellites (CGMS)

Current Polar-Orbiting Satellite Coordinated Within CGMS (as of July 1998) Orbit type (equatorial Satellites in orbit Operator Crossing Launch Status crossing times) (+operation mode) time date P=pre-operational A=North Op=operational D=South B=back-up +Altitude L=limited availability Sun-synchronous NOAA-15 (Op) USA/NO AA 0730 (D) 05/98 Operational -· Primary AM "Morning" NOAA-12 (Op) USA/NO AA 0640 (D) 05/91 (0600--1200) 850km Functional (except sounding) (1800-2400) NOAA-11 (Op) USA/NO AA 0720 (D) 09/88 NOAA-12 (Op) NOAA-10 (B) USA/NO AA 1000 (D) 12/86 Sounding only 840km DMSP-F14 (Op) USA/NO AA 2042 (A) 04/97 Search and Rescue only DMSP-F12 (B) USA/NOAA 2113 (A) 8/94 Defense satellite. Data partly available to civilian users Defense Satellite. Data partly available to civilian users Sun-synchronous NOAA-14 (Op) USA/NO AA 1400 (A) 12/94 Operational - Primary PM "Afternoon" 850km (1200-1600) (0000-0400) - Sun-synchronous DMSP-1'13 (Op) USA/NO AA 1740 (A) 03/97 Defense satellite. Data partly available "Early morning'' 850km to civilian users (0400-0600) DMSP-Fll (B) USA/NO AA 1912 (A) 11!91 (1600--1800) 850km Defense Satellite. Data partly available to civilian users Non sun-synchronous METEOR 2-21 (Op) Russian Fed. 950km 08/93 Functional, except IR scanning instruments or unspecified orbits METEOR 3-5 (Op) Russian Fed. 1200 km 08/91 Functional, except IR scanning instruments - lll-8 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENTATION

Table 5 (continued) Current Geostationary Satellite Coordinated Within CGMS (as of July 1998) Sector Satellites currently Operator Location Launch Status in orbit (+type) date P=pre-operational 0p=operationa1 B=baok-up -L=limited availability . East-Pacific GOES-10 (Op) USA/NO AA 135'W 04/97 (!80'W-108'W) West-Atlantic GOES-8 (Op) USA/NO AA 75'W 04/94 Minor sounder anomalies (108'W-36'W) GOES-9 (B) USA/NO AA 105'W 05/95 In stand-by East-Atlantic METEOSAT-6 (B) EUMETSAT 11/93 Minor gain anomaly on IR imager (36'W-36'E) METEOSAT7 (Op) EUMETSAT o· 02/97 Functional Indian Ocean METEOSATS (Op) EUMETSAT 63'E 03/91 INDOEX Experiment, functional (36'E-108'E) GOMS-N1 (P) RUSSIA 76'E 11/94 Disseminates 3-hourly IR images FY-2 (L) CHINA 105'E 06/97 Experimental Satellite INSAT II-B (L) INDIA 93.5'E 07/93 Cloud imagery for domestic use but INSAT 1-D (L) INDIA 83°E 06/90 wind products available on WMO GTS West -Pacific GMS-5 (Op) JAPAN 140' E 03/ 95 Operational (108'E-180'E) GMS-4 (B) JAPAN 120'E 09/89 In stand-by

Future Polar-Orbiting Satellites Coordinated Within CGMS (as of July 1998) Orbit type Future additional Operator Planned launch date Other information (equatorial crossing times) satellites Sun-synchronous METOP-1 EUMETSAT 2003 (827 km) (0930) "Morning" METOP-2 EUMETSAT 2007 (827 km) (0930) (0600-1200) METOP-3 EUMETSAT 2010 (827 km) (0930) (1800-2400) METEOR 3M-1 Russia 8/1999 (1030) METEOR 3M-2 Russia (TBD) RESURS 01-N4 Russia 1998 Partly met. Mission Sun-synchronous NOAA-L USA/NO AA 12/1999 (1330) "Afternoon" NO AA-M USA/NO AA 04/2001 (1330) (1200-1600) NOAA-N USA/NO AA 12/2003 (1330) (0000-0400) NOAA-N USA/NO AA 07/2007 (1330) NPOESS-1 USA/NO AA 2008 (1330) NPOESS-3 USA/NO AA 2013 (1330) Sun-synchronous DMSP'SlS USA/NO AA 1999 "Early morning" DMSP-S16 USA/NO AA 2001 (0400-0600) DMSP-S17 USA/NO AA 2002 . (1600-1800) DMSP-518 USA/NO AA 2003 DMSP-S19 USA/NO AA 2005 DMSP'S20 USA/NO AA 2007 NPOESS-2 USA/NO AA 2010 NPOESS-4 USA/NO AA 2016 Non sun-synchronous FY-1 C China 1999 or unspecified orbits FY-1 D China 2001 of receivers. WMO Members throughout the world QUALITY OF OBSERVATIONAL DATA operated a total of 1 177 satellites at the end of 1998. The overall WMO percentage of implementation is 79 per 22. The quality of observational data is regularly cent, an increase from 70 per cent in 1997. This increase monitored and reported on under the WWW Data is due in part to the donation by Switzerland of 30 Quality Monitoring Plan as given in the Manual on the satellite receivers to countries that previously had no Global Observing System (WMO-No. 544). That plan was receiving capability. Over the next 10 years starting in implemented in 1988 and is now used globally. The about 2000, APT and WEFAX Low Rate Picture monitoring is carried out by lead centres as follows: Transmission (LRPT) and Low Rate lnformation Transmission (LRlT) receivers will replace the Data type Area of responsibility present receivers. The transition may cause some RSMC/ECMWF upper-air data -- global fluctuation in the percentage of implementation for the RSMC Bracknell surface marine data- global various regions. WMC Washington aircraft and satellite data - global THE GLOBAL OBSERVING SYSTEM lll-9

Table 5 (continued) Current Geostationary Satellite Coordinated Within CGMS (as of July 1998) Sector Future additional Operator Planned launch date Other information satellites East-Pacific GOES-L USA/NO AA 1999 13S"W (180"W-108"W) GOES-M USA/NO AA 2002 and GOES-N USA/NO AA 2002 7S"W GOES-0 USA/NO AA 2005 West-Atlantic NOAA-P USA/NO AA 2007 (180"W-36"W) NOAA-Q USA/NOAA 2010 (East-Atlantic MSG-1 EUMETSAT 2000 0" (36"W-36"E) MSG-2 EUMETSAT 2002 0" MSG-3 EUMETSAT 2006 0" Indian Ocean GOMS-N2 RUSSIA 76'E (36"W-36"E) INSAT li-E INDIA 1998 83"E INSAT li-A INDIA end 1999 INSAT li-D INDIA 2002 105"E FY-2B CHINA 2000 West-Pacific MTSAT-1 JAPAN 08/1999 Multi-functional Transport (108"E-180"E) MTSAT-2 JAPAN 2004 Satellite 140"E ....

~--. -~------1*"";;~~-~,,,, ..1111 IIZ

Figure 7- The total number of satellite receivers in each WMO Region biannually from 1990 through 1998 is shown.

RSMC Nairobi land surface observations- RA! reports are distributed to Members so that they can take RSMC Tokyo land surface observations- RAll remedial action if necessary. RSMC Buenos Aires land surface observations- RAlll RSMC Montreal land surface observations- RAlV UPPER-AIR DATA QUALITY WMC Melbourne land surface observations- RAV RSMC Offenbach land surface observations- RAVI 24. The number of upper-air stations monitored each month by RSMC ECMWF varied from 900 to 950. On 23. The lead centres generate monthly or six-monthly the basis of the monitoring carried out during the peri­ reports on the results of data quality monitoring. These od July to December 1996, 105 stations (excluding lll-10 WORLD WEATHER WATCH- NINETEEI\TH STATUS REPORT ON IMPLEMENTATION

90 -----

;;; 0 70 "']"" u 60 0 ~ ~ ~ 50------··------1 "S ;;;;~ ~ 40- 0 ·------+------+- ~ g,"" 30 --+------1 ~ 8 ~ i ""' 20 +------+----·-----+------! 10 --+- 0 1992 1996 1998 --:64::=.-----+---- 71 82' 73 74 91 7T 92 100 ------68 ------43

Figure 8 - The percentage of Members in each Region reaching implementation goals for satellite receivers for 1992, 1996 and 1998 is shown. stations from block numbers 42 and 43) reported suspect MARINE SURFACE DATA QUALITY geopotential heights, and 70 stations reported suspect winds. Remedial action taken by Members resulted in 26. RSMC Bracknell undertakes monitoring of the about 10 per cent of the stations originally considered as quality of certain variables contained in SHIP reports suspect raised to acceptable levels in 1997. However, received via the GTS. The most important of these vari­ 51 other stations reported suspect geopotential height, ables is surface pressure. Monitoring allows the and 31 others reported suspect winds during the second identification of those ships which report consistently half of 1997. low quality (root-mean-square (RMS) deviations above a certain level compared with first guess field) pressure LAND-SURFACE DATA QUALITY observations over a period of time. The six-monthly monitoring reports are distributed to Port Meteoro­ 25. On the basis of the monitoring carried out by lead logical Officers in those NMSs that have recruited the centres Nairobi, Tokyo, Montreal, Melbourne and identified ships, with a request to undertake remedial Offenbach during the period July to December 1996, 55 action. The effectiveness of both the monitoring and fol­ stations reporting suspect atmospheric pressure observa­ low-up actions was confirmed by the fact that the tions were identified. Sixteen of these stations, or 30 per number of ships having consistently bad pressure obser­ cent, applied effective correctional measures in 1997, vations fell from around 50 to 60 to a reasonably and have been taken off the consolidated lists of suspect constant level of 20 to 25 ships per month. The numbers stations. However, some other stations appeared in the would undoubtedly rise again if the monitoring and fol­ lists of suspect stations, so the overall number of stations low-up were discontinued. reporting suspect atmospheric pressure at the end of 27. A number of major meteorological centres under­ 1997 was 60. Some examples of types of errors which take real-time monitoring of the quality (compared with have been documented are use of a wrong elevation, the first-guess model fields) of variables reported by drift­ errors in the reduction to mean sea level, use of an incor­ ing buoys, and received via the GTS. The monitoring rect station pressure, and problems with consistency of results are relayed to buoy operators through an Internet barometer readings. mailing list (in the context of Quality Control Guidelines THE GLOBAL OBSERVING SYSTEM 111-11 recommended by the Data Buoy Cooperation Panel to less than 1.2 hPa since 1987 (Figure 9.) The mean dif­ (DBCP)). The positive results of the operation of these ference is now probably close to the uncertainty in the guidelines are seen in the RMS difference between model. The improvement in quality of these observa­ buoy air pressure observations and the first-guess tions is significant and due principally to improvements model field. lt has decreased from around 3 hPa in the quality of the pressure sensors.

Mean (Obs.-FG), air pressure (from ECMWF monitoring statistics)

Global drifting buoy data 1987 to July 1998

87 88 89 90 91 92 93 94 95 96 97 98 Year Figure 9- RMS differences between buoy air pressure observations and the first-guess model field for the years 1987 to 1998. (A gap of observations during 1997 was due to a telecommunications failure.)

CHAPTER IV THE GLOBAL TELECOMMUNICATION SYSTEM

1. The GTS is organized into three levels- the MTN, DATA-COMMUNICATION TECHNIQUES AND the RMTNs and the NMTNs. The MTN is the backbone PROCEDURES of the GTS, connecting Regions through major RTHs; the RMTNs connect WWW centres within a Region; and 2. The GTS adopts standard data-communication the NMTNs connect the meteorological stations or cen­ techniques, protocols and applications to the largest tres of a particular country. Figures 1, 2, 3 and 4 depict extent possible, with a view to improving the cost-effec­ the general structure and status of implementation of tiveness of facilities. The GTS also benefits from new the GTS. In summary, some 16 per cent of the GTS is not telecommunication means, services and equipment. implemented as per Figure 2. Most implemented circuits These are widely supported by telecommunications are medium speed (Figure 3). The largest difference in providers and manufacturers. Using these industry stan­ the recommended level and actual level of implementa­ dards results in direct savings to Members by reducing tion is in Region 1 (Figure 4). costs for communications equipment purchase and

Satellite Two-way System

Figure 1- Structure of the GTS.

53% 46%

Medium speed • (1.2 kbitjsec-38.4 kblt/sec) ~~Telegraphic Low speed (less than • 1 200 bit/sec) Ill Not operational 11 Not operational

Total number of circuits: 298 Total number of circuits: 298 Figure 2 - Implementation of circuits in the GTS. Figure 3- Speed of circuits in the GTS. IV-2 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENTATION

would cause the need for more spectrum-efficient radiosondes (frequency stability, narrow-band) and would significantly increase the operational costs of radiosonde networks. In view of the considerable diffi­ culties already experienced by many Members in meeting upper-air observation requirements, any cost increase would have a detrimental impact on meteoro­ logical operations, particularly in developing countries.

MULTI-POINT TELECOMMUNICATION SERVICES

Rogloo I Roglon 11 Raglan Ill Region IV Fblglon V Region VI MTN lnterreglonol VIA SATELLITE AND RADIOBROADCASTS Figure 4 - Status of implementation of GTS by Region Ganuary 1999). 4. There has been extensive implementation of satel­ lite-based multipoint telecommunication systems. These maintenance, as well as reducing the human resources are essential components of the GTS and comprise both needed for software development. The data-communica­ commercial telecommunications and environmental tion protocol specified in ITU-T Recommendation X.25 satellites. Each WMO Region is completely covered by at has been the GTS standard for several years. CBS has least one satellite distribution system. These systems agreed that TCP /lP should replace X.25 for GTS opera­ effectively complement point-to-point circuits, particu­ tions. The transition to TCP/IP from X.25 was larly in the delivery of processed meteorological considered appropriate because TCP /lP has become a de information to NMCs. facto standard that is flexible, versatile and widely avail­ 5. I-IF broadcasts have high recurrent operational able, and because vendor support for X.ZS technology costs and limited operational effectiveness. has been declining and becoming more expensive. - Consequently, several Members have discontinued their HF broadcasts, in some instances replacing them with RADIOFREQUENCIES FOR METEOROLOGICAL satellite distribution systems. HF broadcasts may still be ACTIVITIES required in some areas, mainly at the regional level. In the maritime community, more effective distribution 3. The radiofrequency allocations to meteorological systems, such as the International Maritime Satellite aids (radiosondes) and satellites face a continuing threat Telecommunications Organization (INMARSAT), within by the telecommunication industry, which is planning the framework of the Global Maritime Distress and future mobile ~atellite systems (Low-Earth Orbiting Safety System (GMDSS), are in rapid development. satellites (LEOs)). At the 1997 WRC, coor.dination between Meteorological Services and WMO resulted in MTNs measures to safeguard radiofrequency allocations for meteorology. But the threat, particularly to radiofre­ 6. All 23 MTN circuits are in operation and all MTN quency bands 401-406 MHz and 1675-1710 MHz, will centres are automated. Eight out of 23 circuits use digi­ continue at least until the next WRC in 2000. Any tal technology at speeds from 64 to 128 kbit/s. Except for reduction of bands allocated to meteorological aids the telegraphic circuit New Delhi-Cairo (lOO Baud), the

IN THE 70s

mostly 50-75 bit/s, a few 2400 bit/s

64 Tokyo

9,6 Cairo New Delhi 9.6 ~==;-'\ 0.1 Jeddah

9.6

64 IN THE 80s Nairobi 64 [ Brasilla mostly 50-2400 bit/s In 1999 several 9600 bit/s Mostly 9.6 kbitJs, X.25, TCP/IP, several 64 kbit/s Melbourne Buenos Aires

Figure 5-The MTN from the 1970s through the 1980s to 1999. THE GLOBAL TELECOMMUNICATION SYSTEM IV-3 Table 1 Satellite-based telecommunication systems by WMO Region. Region Complete or near-complete coverage by: Partial coverage by: I ISCS (Atlantic) RETIM MDD' UKSF/WWW FAX-E

ll UKSF/WWW" ISCS (primarily Pacific) MDD MTSAT (planned for March 2000) TV-Inform-Meteo Systems operated by China*, India and Thailand

Ill EMWIN-E MDD ISCS (Atlantic) and ISCS (Pacific) System operated by Argentina

IV EMWIN-E MDD ISCS (Atlantic)' and ISCS (Pacific)

V ISCS (Pacific)'" EMWIN-W MTSAT (planned for March 2000)

VI MDD FAX-E' ISCS (Atlantic) RETIM' UKSF/WWW Component of the RMTN ** Pilot project *** Integration into the RMTN under consideration

MTN circuits were operating at data rates greater than to high speed (2.4 up to 64 kbit/s). Most of them use the 4.8 kbit/s. All but one of the MTN circuits currently use X.2S protocol. There are still a large number of interre­ X.2S protocol and a few centres are supporting passage gional and regional circuits that operate at low speeds of of non-adjacent traffic. Several MTN centres already SO to 100 baud. The DCS, Data Collection Platform have firm plans for the introduction or further imple­ (DCP) and the MDD operated via METEOSAT satellites mentation of TCP/lP procedures on MTN and other GTS remain essential components of the GTS in Region I. circuits, as well as for their NMTN. Figure S shows the Four RTHs and one RSMC operate radiobroadcasts. evolution of the MTN from the 1970s through the 9. The development of subregional networks such as 1990s. the very small aperture terminal (VSAT) network coordi­ nated by the Agency for Air Safety in Africa and RMTNs Madagascar (ASECNA) in the western and central parts of Africa, and the planned Southern Africa Development 7. Significant progress has been made in implement­ Community (SADC) network in the southern part, ing RMTNs and connecting them to the MTN, but provide promising solutions for upgrading the RMTN in serious shortcomings still exist in some Regions. The the very near future. Collection of observational data detailed diagrams of implementation of the RMTNs are remained unsatisfactory (less than SO per cent) due to provided in Annex I. Table 1 lists telecommunications national difficulties in implementing and maintaining systems in place in each WMO Region. equipment. Telecommunication services normally avail­ able from local services are often at costs not affordable STATUS OF IMPLEMENTATION AND OPERATION for some NMHSs. The DCS/DCP via METEOSAT contin­ OFTHEGTS ued to be an essential component for data collection in this region. RA I RA II 8. There have been significant improvements in the implementation of RMTN point-to-point circuits in 10. Twenty-two interregional and regional circuits Region I (Figure 6). The regional loop linking RTHs operate at medium to high speed (1.2 up to 64 kbit/s); Algiers, Dakar, Niamey, Nairobi and Cairo has been most of them used the X.2S protocol, while 31 circuits improved, with support from RTH Toulouse, to ensure a still operate at low speeds of SO to 200 baud in Region 11 top-priority, fast exchange of meteorological informa­ (Figure 7). The observational data collection system in tion. Nineteen interregional and regional circuits Region 11 is in general quite satisfactory, except in a few operate via telephone-type circuits, public data network countries where serious shortcomings still exist. Nine services or even digital circuits, and transmit at medium RTHs operate radiobroadcasts. Some countries in this IV-4 WORLD WEATHER WATCH -NINETEENTH STATUS REPORT ON IMPLEMENTATION region, including China, India, the Russian Federation GTS component has been integrated into the RMTN to and Thailand, operate satellite-based telecommuni­ strengthen meteorological data distribution . The DCS of cations systems for national purposes. A pilot project is both the geostationary meteorological satellite (GMS) being developed for improving the dissemination of and geostationary operational environmental satellite meteorological data and products via the United (GOES) satellites plays an increasing role for collecting Kingdom Satellite Facilities (UKSF), which also supports observational data. The GOES EMWIN (Emergency the Satellite Distribution System (SADIS). Satellite-based Managers Weather Information Network), the telecommunications are being explored as a way to INMARSAT system, as well as Public Data-communica­ upgrade the RMTN. tion Networks and the Internet, are operated or planned for improving the RMTN, particularly with respect to RA Ill small nations in the Pacific. The two RTHs operate radio­ broadcasts. 11. In Region Ill, the three RTHs are interconnected via medium-speed circuits, but most of the NMCs are con­ RA VI nected via low-speed circuits that cannot meet current requirements (Figure 8). A satellite-based data distribu­ 14. In Region VI, the large majority of interregional tion system is operated by RTH Buenos Aires. All 13 and regional circuits operate at medium or high speed NMCs are equipped with World Area Forecast System using the X.25 or TCP/IP protocol (Figure 11). Point-to­ (WAFS) receiving systems via the International Satellite point circuits are complemented by two satellite-based Communication System (ISCS) operated by the United distribution systems: RETIM operated by France, and States of America. RA Ill is developing a project to FAX-E operated by Germany. In particular, these are upgrade the RMTN using a new Managed Data­ meant to improve the delivery of data and products in Communication Network that is commercially provided. the eastern and south-eastern part of the Region. Three RTHs also operate radiobroadcasts. Establishing the RAIV Regional Meteorological Data Communication Network (RMDCN) has been the major effort of RA VI. The 12. In Region IV, the RMTN mainly consists of a two­ RMDCN will be implemented in 1999 using a shared way satellite-based network implemented via ISCS Managed Data-Communication Network that is com­ (Figure 9). This RMTN is fully operational in all countries mercially provided to which NMCs and RTHs will be except Haiti, and prQvides for a medium/high-speed connected. This service will replace all current point-to­ connection between NMCs and WMC/RTH Washington. point circuits. The RMDCN will meet RA VI GTS require­ The NMCs have iilso been automated through the instal­ ments as well as data exchange requirements between lation of the associated computer-based terminals for ECMWF and its Member and Cooperating States. handling data and processed information. A few medi­ 15. HF broadcasts have high recurrent operational um/high-speed circuits complement the satellite-based costs and limited operational effectiveness. network. Consequently, several Members have discontinued their HF broadcasts, in some instances replacing them RAV with satellite distribution systems. HF broadcasts may still be required in some areas, mainly at the regional 13. In Region V, the RMTN comprises 16 interregional level. In the maritime community, more effective dis­ and regional circuits operating at medium or high speed, tribution systems, such as INMARSAT (within the using the X.25 or TCP/IP protocol (Figure 10). Links to framework of GMDSS), are in rapid development. small nations in the Pacific are extremely difficult to Results of the annual global monitoring of the opera­ implement in a cost-effective manner. The ISCS is being tion of WWW from 1 to 15 October 1998 are implemented to support the WAFS distribution, and its summarized in Annex I. g:==""'"'"'"~l- -- ...... :-sO! lli~:~~;,~]t =:Moscow:: "", a i!l_Oi!~;,====,=::::=::,==B :~:::-..::-:.:::::::::::::~::;' ... ' 100 -~New Delhi~j \ ~.:::::::.. ..:::::::::::: .. .>: l

r­ •50 I ,_ .. , 'T-' I Ouagadougou I

r 5! tti -, 150 I p,... 0 't •75' ~ ~ "'[": ~ A=r,·~~~.--~ ~ tti n ,175:J __ ;;::~ ~ :;n ~ ~ D ~ D c::::J r---, MTN circuit, circuit RPT llJi)ltliJ ------: 2400 1 = flEP.i!l HF circuit -----;---z Regional loop, boude ligionale Regional circuit, circuitn\gional

Interregional circuit, circuit inter-regional

NI Not implemented NO Not operational Figure 6 - RMTN for Region I (Africa) point-to-point circuits implementation (transmission speed in bit/s). ~ ~ [~~7~~

f"64ooo 1 ~~~~~.~. ·---~

~~~~~~ B IShk e k !\ ;-; -~--· ·'!."1r I 0 ~- ' ; B"' ;;i

:I: "' ~~.Q~ ~ r ~ ~~~=~ g I @)_ I ~~ NewDelh~ ~o' ,. z 11 I I I " I ~ ·-· "' [;.;£·~ '· 70; ~ ~ :' =~=::::::=::::::.,: :;! ~b~~~j g ~ !f"~~~--1! 0 ih::::::::::::di 2'l 0 RTH z ~------:~~: fl D<1HY..Ul\. I D ~ ,-'::.. ( NMC D ,1~0£, ~'~-,,=,~:r ;-··-····l •·•·-•A...... t~~~~~;JI ~ L .. _..J Centre in atherregion L..r:~.~-~:.~~.J ~ MTN circuit Regional circuit "'~ Interregional circuit 15.XII_l998 Nl Not implemented

Figure 7 - RM1N for Region 11 (Asia) point-to-point circuits implementation (transmission speed in bit/s}. .. ~ [~~~!:]! .--

5! :Mooo-: "' L ·----· "5 r- ~ --, :_9~~~! 1 75 1 ·--- _} 0 =~ ~ n RTH • ..a-1 ----. 1 1 D 75 I 64QQQ I I ____I 0 D NMC '--~ z"' [~:~] Centre in other region MTN circuit r ' ~ \ \ 1 ~ Regional multipoint circuit ~ via satellite (V SAT) Regional circuit

Interregional circuit

N/0 Not Operational

NO Not operational

Figure 8-RMTN for Region III (South America) point-to-point and multipoint circuits implementation (transmission speed in bit/s). 1 " 1Ol 't ..!======~:~::~~:~~;.~::::::!1

~--~~..-.~~~~~~~~--~~--~~--~--~ I M•-'( c,- ;· ·---,·~""-""" ___ :~....~ .... ~.:...~· ....~ ....;;;; ..... ~ ...; .... ~ ... ~~;~ 'R.-r<><';l~- : ~! Buenos . }=::: ._,:_. 'v_ ·--- ~ ~ ~ o;AITes ti ::;; \. ·~- '\ ~ ~ I "'" -~~~~ ~~ g~ ,------V \/ ~ I''M•~-J I ~ 1'·~-·r-/ ,_m, . .- _\/ ~ ~ ~ 5:! d ~~~ ~ Gl ~ '\ --'\ ~ 0'"" "'-.)_ !:l 0Rm ~ ~t :@ D NMC s ~ :f §:: ...... , anJose I ~) I StVincent I •...... J Crntromoili~regooo g. ~ Port of Spain ~-. z · •. :;! " Panruna ...... •...... ::l ;;:~;~~~:~wremo " , :@ . Georgetown ~ 384kb/sRec& l]kb/s Trans ~ ~-, '-...... • GOES data collection / ···············-·····: Regional circuit ~, Cayenne j '························ •••••••• R .... Interregional circuit

Figure 9- RMTN for Region IV (North and Central America) point-to-point and multipoint circuits implementation (kbit/s). GMSDCPs

/ 1 ..~ :-_~"_) ...... , - - < ;; Washington ;; !3~2] ""'""'"!'·""""'""""'

iF:::::::::::::::::::::.-:~ !! Bartgkok ~ '"'l"",w·"·"'r ~( :_~1;,~_!A_b~sJ,---'--· T ,_J., \ :'------·9 6- x25: I Honolulu ,.... -··· !1.2: r---.l--1 -;- •2.4 X.25• 64 I I :t \ .. X.25 I ·---- -· ---- _, Cl"' ~I § [~;,;,;;~IJ \\. ,______2.4 X.251 , F: I ;;l r------\ .\\..• _ 1 -,· ...._.2.4X.25! ~ ~ 1 -I PortMmesby I Honiara I

RTII arta r-L:!I D ··.\·········,··-,,, --- -1 ,-- -, 4.8 i :~~~~-~~H Nadi I I 0.0751 ~ I Q.Q75t NMC '---..::-' --.. '--.--· 8 D ~9.6 : ~ Centre in other region X.25 I : " !48-x-.;:;( c::::J ······-··--············-···-.... L-----' ------· ~ l'viTN circuit t::

Regional circuit

Interregional circuit ;v radio broadcast

~milltipoinl >Y•~m vi• ""'""

NO Notopffational

Figure 10- RMTN for Region V (South-West Pacific) point-to-point drcuits implementation (transmission speed in Kbit/s). ~ "' i 0

::E ::ii 5 ::E '" 0:: ""~ ~ Cl 0:: I z ~ "' ~ ~ ;:! :::! ~ i:l 0'"" ::l ~ §: DRTH ;si ~z DNMC ;:! :···-···~ ::l ! i Centre in other regi_on i ...... ; ~ = MTN circuit Regional circuit

Interregional circuit

NI Not implemented NO Not operational

Figure 11 - RMTN for Region VI (Europe) point-to-point circuits implementation (transmission speed in kilobit/s). CHAPTER V THE GLOBAL DATA-PROCESSING SYSTEM

1. The GDPS consists of WMCs, RSMCs and RSMCs WITH GEOGRAPHICAL SPECIALIZATION NMCs. A count of each type from 1990-1998 is shown in Table 1. WMCs Melbourne, Moscow and Washington 2. The location of RSMCs is shown in Figure 1 of the continued to develop their Global Forecasting Systems. 28 RSMCs indicated, 25 have geographical specializa­ WMC Washington is disseminating WAFS Products for tion (namely, Algiers, Beijing, Bracknell, Brasilia, Buenos aviation worldwide through the lSCS. WMC Moscow Aires, Cairo, Dakar, Darwin, Jeddah, Khabarovsk, has upgraded its computer equipment with two CRAY Melbourne, Miami, Montreal, Moscow, Nairobi, New Y-MP machines, enabling the running of a Global Delhi, Novosibirsk, Offenbach, Pretoria, Rome, Model. WMC Melbourne has upgraded its computer Tashkent, Tokyo, Tunis/Casablanca, Washington and system with an NECSX-4 supercomputer, by which all Wellington). These centres provide regional products to the NWP models are run. Details of the daily output of assist NMCs in the forecasting of small-scale, mesoscale products (analyses and forecasts) of WMCs are given in and large-scale meteorological systems. the annual WWW Technical Progress Reports on the 3. The arrangements for the provision of meteoro­ GDPS. logical assistance to United Nations humanitarian

Table 1 Number of GDPSs grouped by type (WMCs, RSMCs and NMCs) and by forecast models from 1990 through 1998. The categories are exclusive: i.e., tbe WMCs are not recounted among the RSMCs or tbe NMCs. RSMCs are not re-counted among tbe NMCs. Detailed information is available in the WWW Technical Progress Reports on tbe GDPS.

Type of Year Number of GDPS centres centre By type Using computers for Running forecast models NWP Global Hemispheric Limited area High resolution (> 35 km) mesoscale WMCs 90 3 3 2 2 3 0 92 3 3 2 2 3 0 94 3 3 2 2 3 0 95 3 3 2 1 3 1 96 3 3 2 1 3 1 98 3 3 3 1 3 2

RSMCs 90 25 15 6 2 14 1 92 25 15 7 1 14 3 94 25 16 8 I 14 4 95 26 18 10 1 17 4 96 26 20 10 1 zo 4 98 28 25 10 0 22 6

NMCs 90 133 15 0 0 15 1 92 141 19 1 1 19 4 94 155 22 1 1 20 7 95 155 23 1 0 23 7 96 155 24 2 0 24 7 98 156 25 2 0 25 10

TOTAL 90 161 33 8 4 32 2 92 169 37 10 4 36 7 94 183 41 11 4 37 11 95 184 44 13 2 43 12 96 184 47 14 2 47 12 98 187 53 15 1 50 18 V-2 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENTATION mrsswns by RSMCs have been approved by WMO covers RA I and the western part of RA II. Most RSMC and are defined in the Manual on the Global Data­ operations have shown sustained improvement in RAs processing System (WMO-No. 485, Appendix 1.5). Since 11, Ill, IV, V and VI, where they have enhanced their fore­ Washington agreed to provide backup services to Unit

GDPS CENTRES

60'N

'' ' ... o:

I i ,'·· ".

Figure 1 - Locations of RSMCs.

'"' ,.,

Figure 2- Types of numerical models and the GDPSs. THE GLOBAL DATA-PROCESSING SYSTEM V-3 Table 2 Types of Numerical Models running at RSMCs and NMCs. The resolution, number of levels, forecast range, and method of dissemination of the model are indicated. This table is based on the latest information available in 1997 and 1998.

NMC = National Meteorological Centre; GM = Global Model; HM = Hemispheric Model; LAM= Limited Area Model; MSM = Mesoscale Model (resolution higher than 35 kilometres); RSM = Regional Spectral Model; RSMC = Regional Specialized Meteorological Centre with NCMRWF = National Centre for Medium-range Weather Forecasting G = Geographic specialization TM = Transport Model responsibilities TC =Tropical Cyclone responsibilities

REGION I

Centre Status Models Resolution Levels Range Dissemination

ACMAD Special Centre access to GM Fax; Special LAM (RSM) 50 km 28 36h HA RARE Special Centre Special LA REUNION RSMC TC full access to GM GTS; Fax; Satel1ite; Special LAM ALGIERS RSMCG CAiRO RSMCG LAM (ETA) 55 km 32 24 h Fax CASABLANCA RSMCG MSM 16.5 km 27 48 h GTS; Special DAKAR RSMCG GTS; Fax NAIROBI RSMCG access to GM GTS; Fax LAM (RSM) 50 km 28 48 h PRETORIA RSMCG GM T62 28 5 days GTS; Fax Ensemble 10 members T62 16 days LAM 48km 38 48 h TUNIS RSMC G LAM (ETA) 0,5° 32 48 h

RllGIONII

Centre Status Models Resolution Levels Range Dissemination

BANGKOK NMC LAM HANOI NMC LAM HONG KONG NMC LAM (OLAM) 1' 13 72h PYONGYANG NMC LAM SEOUL NMC GM T106 21 120 h LAM 40km 23 36 h Typhoon (KTM) E70 8 60h TEHRAN NMC LAM ULAANBAATAR NMC LAM NCMRWF-INDIA Special Centre GM T63 16 BEI]ING RSMCGTM GM T106 19 10 days GTS; Fax; Satellite LAM (HLAFS)' 0.5° 20 48 h LAM (MTTP" Tropical) SO km 15 48h Ensemble 12 members T63 16 1 month )EDDAH RSMC G Fax KHABAROVSK RSMC G LAM 100 km 11 48 h Fax NOVOSIBIRSK RSMCG LAM 40km 15 48 h Fax TASHKENT RSMCG LAM 250 km 10 36 h Fax NEW DELHI RSMC G TC full access to GM (NCMRWF) T63 16 GTS; Fax LAM (LAPS) I' 12 48 h LAM (nested) 0.5° 16 48 h TOKYO RSMCGTMTC GM (GSM9603) T213 30 192 h GTS; Fax; Special Ensemble 10 members TZI 2 1 month MSM (RSM9603) 20km 36 51 h Typhoon (TYM) 40km 15 51 h "' Heavy rainfall forecast model over the whole Eastern-Asia. ** Model for the Typhoon Track Prediction. V-4 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENTATION

REGION 1II

Centre Status Models Resolution Levels Range Dissemination

INPE-SAO PAULO Special Centre GM (CPTEC/COLA)' T62 28 6 days Special LAM (ETA) 48 km 38 60 h Ensemble 9 members One month BRAS!LIA RSMCG full access· to GM GTS LAM BUENOS AIRES RSMCG LAM 10 36 h GTS; Fax

* Centro de Previsao de Tempo e Estudos Climaticas/Center for Ocean*Land-Atmosphere Interactions.

REGION IV

Centre Status Models ResOlution Leve./s Range Dissemination

MONTREAL RSMCGTM GM 1199 Variable 21 240 hand GTS mesh 360 h Ensemble 12 members T63 21 100 days LAM 35 km 28 48 h MSM (HIMAP) 15 km 35 24h MIAMI RSMC GTC full access to -GM Satellite and LAM HCN (hurricane) 0.16° 18 72h WASHINGTON WMCRSMCGTM GM T170 42 7 days GTS; !SCS (WAFS); Special GM T62 42 7 to 16 days LAM (RUC) 60km 25 12 h MSM (Mesa-ETA) 29km 50 33 h MSM (ETAIO) 10km 60 33 h RSM (Hawaii) 10km 28 48 h Ensemble 17 members T62 28 16 days

REGION V

Centre Status Models Resolution Levels Range Dissemination

SINGAPORE NMC and ASEAN GSM 1.875° 16 240h Special Specialised LAM (FLM) 127km 12 48 h M.eteorological LAM (VFM) 63 km 13 48 h Centre (ASMC) DARWIN RSMCG full access to GM LAM (TLAPS) 0.75° 19 48 h GTS; FaX; Satellite; Special NADI RSMCTC GTS; Fax WELLINGTON RSMC G LAM Fax MELBOURNE WMCRSMCGTM GM T79 19 240 h GTS; Fax; Satellite; LAM 0.75' 19 48 h Special (TLAPS) 0.75° 19 48 h MSM (MESO-LAPS) 0.25' 19 36 h

··--~-----.. ··-·· THE GLOBAL DATA-PROCESSING SYSTEM V-5

REGION VI

Centre Status Models Resolution Levels Range Dissemination

ANKARA NMC full access to GM (ECMWF) LAM 0.5' 17 48 h ATHENS NMC full access to GM (ECMWF) LAM (ETA-NMC) 0.21' 32 48 h MSM (nested) 0.07' 32 24 h BELGRADE NMC LAM (ETA 95) 46km 32 48 h BET DAGAN NMC LAM 180 km 16 24 h BRUSSELS NMC Full access to GM (ECMWF) MSM (ALADIN) BUDAPEST NMC LAM 0.9° 12 36 h COPENHAGEN NMC Full access to GM (ECMWF) LAM (HIRLAM-G) 0.45' 31 60 h LAM (HIRLAM-N Greenland) 0.15' 31 36 h LAM (HIRLAM-E) 0.15° 31 48 h MSM (HIRLAM-D) 0.05° 31 36 h DE BILT NMC Full access to GM (ECMWF) LAM (HIRLAM) 0.5' 31 48 h DUBLIN NMC Full access to GM (ECMWF) LAM - MSM (HIRLAM) 0.3' 24 48 h HELSINKI NMC full access to GM (ECMWF) . LAM (ATL) 0.40 31 48 h MSM (EUR) 0.25' 31 36 h KIEV NMC LAM MADRID NMC full access to GM (ECMWF) LAM 0.5° 31 48 h MSM NORRKOPING NMC full access to GM (ECMWF) LAM 0.4' 31 48 h MSM 0,2° 31 36 h OSLO NMC full access to GM (ECMWF) LAM 0.5° 31 48 h MSM PRAGUE NMC LAM 330km 12 36 h WARSAW NMC MSM 17km 31 38 h ZURICH NMC full access to GM (ECMWF) MSM 14km 20 48 h ECMWF RSMC for GM T319 50 240 h GTS; Special Medium-range Ensemble- 50 members T159 31 Special OBNINSK RSMCTM full access to GM - (for RA 11) HM and LAM TOULOUSE RSMCTM GM (ARPEGE) Variable mesh 27 168 h Satellite-RETlM; T42.5 to T521.5 Special MSM (ALADIN) !Okm 27 36 h OFFENBACH RSMCG GM T106 19 168 h Satellite-FAX-E; Special LAM Electrical Model (EM) 0.5° 20 78 h MSM (DM) 0.125' 30 48 h ROME RSMCG full access to GM (ECMWF) Fax LAM 1' 9 48 h . BRACKNELL RSMCGTM GM 60km 30 144 h GTS; Fax; SADIS (WAFS) MSM 12km 38 48 h MOSCOW WMCRSMCG GM (in development) GTS; Fax HM T40 15 120h LAM SO km 9 36 h GROUP OF COUNTRIES MSM 14.7 km 27 48 h (LACE project): Austria, Croatia, (ALADIN-LACE) Hungary, Czech Republic, project run in Slovenia, Slovakia Toulouse V-6 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENTATION Table 3 Main and secondary computers used for data processing at RSMCs and NMCs are shown. The table is based on the latest information in 1997 and 1998.

REGION I

Centre Mainframe (number crnncher) Secondary computer(s) Work stations

ACMAD INTEL-based servers (AMEDIS . PCs system) -SUN SPARC LAGOS PCs (AFDOS system) HARARE IBM PSs- PCs ALGIERS PCs 386 CAIRO IBM 4381 Model 11- 2 VAX 3400 TX MINI- PCs CASABLANCA CRAY ]916 CRAY CS6400 - SUNSPARK 1000 SGI - 3 DEC ALPHA- MOTOROLA DAKAR PCs NAIROBI VAX3900- VAX 11/750 SGI- PCs LA REUNION Work stations PRETORIA CRAY )916 SGI Origin, 3 SGI Indigo- HP 720- SUN PCs TUNIS BULL DPS 7000/40 2 MINI- 20 MICROs

REGIONII

Centre Mainframe (number cruncher) Secondary computer(s) Work stations

ALMATY PCs BANGKOK DATA GEN. MV7800- 2 HP9000 HANOI MINCOMP ROBOTRON MICRO PS HONG KONG 3 IBM RS/6000 590- SGI Power Challenge WSs KARACHI PCs PYONGYANG EC-I055M- IB'.1370/148 PC/AT- PS/2 SEOUL CRAY YMP C90 (Shared) · FUJITSU VPX 220 SUN 2000 · TEHRAN PCs 486 ULAANBAATAR MICRO VAX 3400 NCMRWF-INDIA CRAY XMP-14 2 VAX 8810- VAX 8250 BEIJING CRAY C92/l-128 CRAY ]90- CRAY EL 98/4- YHcz- IBM SP2/32- 2 ALPHA 1000- WSs 2 ALPHA 4000 , .. · ]EDDAH CDC CYBER 962- 2 CDC 910 3 SG -4 VAX- 3 GDC KHABAROVSK COMPAREX 8/830 PCs NOVOSIBIRSK COMPAREX 8/830 PCs TASHKENT IBM 370 (2 4381 P13) PCs NEW DELHI CDC CYBER 2000U CDC 4680 CYBER 910-484 WSs- VAX 3400- 2 VAX 1!/750 TOKYO HITACHI 3800/480 HITACH!3500 HITACHI WSs THE GLOBAL DATA-PROCESSING SYSTEM V-7

REGION IIl Centre Mainframe (number cruncher) Secondary computer(s) Work stations SANTIAGO MICRO VAX- PCs INPE-SAO PAULO NEC SX 4, NEX SX 3 2 DEC Alpha 8200, 5 DEC Alpha 4100 56 WSs, 40 PCs BRASILIA WSs BUENOS AIRES ORIGIN 2000 3 SGI INDIGO- IRIS - INDY

REGION IV Centre Mainframe (number cruncher) Secondary computer(s) Work stations SAN JOSE 2 SUNSPARC VSAT/STAR-HP WS- 12 IBM PCs MONTREAL NEC SX-4/32- NEC SX-4/16 CONVEX 3840- 2 SGI Challenge 17 SGI- 33 HP MIAMI WSs WASHINGTON CRAY C90 2 CRAY }916

REGION V

Centre Mainframe (number cnmcher) Secondary computer(s) Work stations

SINGAPORE NEC SX-3/11 2 FACOM M!600/6 - SUN 8 WKs DARWIN WSs NADI 2 IBM RS6000/}50 WSs, PCs WELLINGTON 9 PARALLEL PROCESSORS WSs MELBOURNE NEC SX-4/16 - 7 HP 9000/800 CRAY Y-MP/4E- CRAY }90

REGION VI Centre Mainframe (number crnncher) Secondary computer(s) Work stations ANKARA CDC 180/830- MICROVAX 2000 ATHENS CONVEX Sl'l'l600-8 ~GI: Z INDIGO- 3 INDY- I ULTRA 8 WSs-IHPWS-PCs BELGRADE CONVEX C240/2 SGI POWER INDIGO, 2 INDY, 302-10 PCs BETDAGAN CYBER 180/830- IBM RS/6000 320H 3 SGI Origin servers 8 SGI WSs BRATISLAVA SUN HPs BRUSSELS CRAY }916 HP servers WSs BUDAPEST HP K200- }210- 755- 715- 710 SUNWS- PCs COPENHAGEN NEC-SX4 (16 processors) 2 SGI CHALENGE WSs DE BILT SGI Power Challenge DEC alpha clusters- WSs DUBLIN MIPS R400 SC-50 R3230 SGI CHALLENGE- 2 VAX 4200- VAX 3!00 HELSINKI CRAY 94/4256- CRAY T3E VAX 6240 VAX Clusters - WSs (128 processors) KIEV EC-1061 PCs LISBON 2 DEC Alpha MADRID CRAY C-94 VAX- HP and SUN (servers) SUNWSs NORRKOPING CRAY C96- CRAY T3E 29 VAX (Clusters)- 7 DEC- SUN WSs (184 processors) OSLO CRAY Y-MP 464 2 SILICON GRAPHIC 4D/340 420 PRAGUE 3 JCL DRS6000 SUN SPARK WKs- 2 TWO- ID ONE WARSAW CRAY YMP4E(shared) IBM AS/400- RS/600 PCs ZURICH CRAY }932/16 SUN (servers) SUNWSs ECMWF FU}ITSU VPP 700 (116 processors) IBM ES/9000-720 - 4 IBM RS 6000 - SG!s indigo -lndy, PCs - VPP 700E (48 processors)- IBM SP- 2 VAX 4100-3 SGI Challenge- VPP 300-(9 processors) - 3 HP K series - 2 SGl Origin 2000- VPP 300 (4 processors) 2 SGI Crimson TOULOUSE FU}ITSU VPP 700 (26 processors) HP 891- 715 OFFENBACH CRAY C98- CRAY T3E CRAY ]932- ORIGIN CYBER 910-400- WSs ROME IBM 3090/12E - 438/13P VAX 2 8250 Cluster- 4000 BRACKNELL CRAY C916/16- IBM 9672-R73 - CRAY T3E MOSCOW CRAY Y-MP98 CRAY Y-MPEL 98 - COMPAREX 8/83 2 HP 735 WSs V-8 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENT/if! ON

RSMCs WITH ACTIVITY SPECIALIZATION 8. The position error statistics for RSMC New Delhi, which runs a LAM, are shown in Table 4. RSMC Miami, 5. RSMCs with activity specialization provide prod­ which runs a Hurricane Track Model on Washington ucts that meet specific requirements, such as NCEP computers, shows a steadily improved forecast medium-range forecasting products, tropical cyclone trend (Figure 4). Position forecast verification statistics forecasting products and transport model products for for warnings issued by RSMC Nadi are shown in Table 5. environmental emergency responses. Forecast errors at both 12 and 24 hours are slightly less in the 1997-98 season than the 1996-97 season and MEDIUM-RANGE WEATHER FORECASTING show a significant improvement over persistence (not shown). RSMC Tokyo runs a Typhoon Track Model and 6. ECMWF is one of the first among the leading GDPS also uses its Global Spectral Model (GSM) for typhoon Centres to implement a four-dimensional variational (4-D tracking. Some high-resolution global models, such as VAR) Data Assimilation System, making use of the massive the ECMWF model, show that they can provide tropical parallel-processor technology. A subset of its products cyclone track forecasts if the cyclones have been proper­ (forecasts of four parameters up to day seven) is dissemi­ ly caught (or bogused) at the data assimilation stage nated on the GTS in GRID and GRIB codes. Details of the (Table 6). daily output of ECMWF products on GTS are given in the 9. Steady progress is observed for the tropical cyclone annual WWW Technical Progress Reports on the GDPS track positions; however much more remains to be done (see summary in box below). A 50-member Ensemble with respect to forecasting the intensity of cyclones. Prediction System (EPS) is run daily and the results are Most RSMCs also apply statistical models to supplement made available to the ECMWF Member States. the results of the physical models.

TROPICAL CYCLONE FORECASTING PROVISIONOFTRANSPORTMODELPRODUCTSFOR. ENVIRONMENTAL EMERGENCY RESPONSES 7. RSMCs Nadi, New Delhi and La Reunion are tropi­ cal cyclone centres; RSMC Miami is a hurricane centre; 10. There are eight RSMCs designated or recommend­ and RSMC Tokyo is a typhoon centre. They all specialize ed for the provision of transport model products in case in tropical cyclone forecasting and related products. Their of nuclear emergencies. They all have implemented the respective areas of responsibility are shown in Figure 3. regional and global arrangements for the provision of

ECMWF products on GTS NORTHERN HEMISPHERE (0-90'N) and SOUTHERN HEMISPHERE (0-90'S): Mean sea level pressure, temperature 850 hPa, height 500 hPa, analyses and forecasts every 24 hours up to day seven (168 hours) . TROPICAL BELT (35'N-35'S): Wind at 850 hPa and 200 hPa, analyses -and fmecasts every 24 hours up to day 5 (120 hours)

All products are delivered in FM 47 GRID at resolution of sox so an.d in FM 92 GRIB at resolution of 2.5°X 2.5°,

EQ

60'S~~.J...-~-~-f~-~-~':'"""~':'"""~-~':'"""~-~::-~11:t'::m~':'"""~-d,.,~~~~-·-.J· 20'W 0 20'E 40'E 60'E 80'E 100'E 140'E 160'E 180' 20'W60'S RA I Tropical Cyclone RA V Tropical Cyclone Committee for the South-West Committee for the South Pacific Indian Ocean and South-East Indian Ocean Figure 3 -The areas of responsibility for RSMCs specializing in Tropical Cyclone Forecasting are indicated. THE GLOBAL DATA-PROCESSING SYSTEM V-9

Table 4 RSMC New Delhi Mean forecast position errors (in kilometres) for tropical cyclones over the Bay of Bengal and the Arabian Sea based on analogue, CLIPER and RSMC forecast models.

RSMC New Delhi Mean Forecast Position Errors for Tropical Cyclones

Year Analogue CLIP ER RSMC

12 h 24 h 36 h 12 h 24h 36 h 24 h

1995 63 191 367 !53 322 633 1996 62 98 164 93 !57 273 261 1997 82 138 246 107 198 188 238

Table 5 RSMC Nadi position forecast verification statistics for official warnings issued for Typhoons over the South Pacific. Forecast positions are verified against the official best track (error in kilometres for corresponding number of forecasts).

RSMC Nadi Mean Forecast Errors in Tropical Cyclones Positions

24 h 48 h 72 h Year Number Error Number Error Number Envr 1996-97 191 31 140 124 117 247 1997-98 318 31 221 113 171 zoo

Table 6 RSMC ECMWF mean forecast errors in geographic position of typhoons position from the medium-range forecast model is shown (error in kilometres for corresponding number of forecasts).

RSMC ECMWF Mean Forecast Errors in Typhoon Positions

24 h 48h 72 h Year Number Error Number Error Number Error 1992 189 28 302 20 465 11 1993 274 32 450 zz 515 10 1994 189 20 252 IS 261 10 1995 194 35 393 25 422 13 1996 190 zz 279 17 316 9 1997 144 16 246 13 315 9

Figure 4- RSMC Miami official track forecast errors for the Atlantic basin over the period 1970 to 1996. Average errors are shown adjusted for difficulty using the best-track CLIPER errors at 24 h, 48 hand 72 h. Vertical axis units are nautical miles. (Source: NOAA) V-10 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENTATION products as defined by WMO in the Manual on the Global the 48- and 96-hour forecasts, but it is less evident for Data-processing System (WMO-No. 485). They provide, the 144-hour forecast range. There appears to be little upon request, specialized transport/ dispersion/deposi­ progress between the two years 1996 and 1997. tion model products in accordance with the Manual, Appendices 1.3 and 11.7. The Centres are: TECHNICAL DEVELOPMENT AT GDPS CENTRES

Centres Area of responsibility 15. Thanks to the enhanced computer power obtained RSMC Bracknell and RSMC Toulouse RA VI and RA I by the use of massive parallel processor technology, SMC Montreal and RSMC Washington RA Ill and RA IV advanced GDPS Centres have implemented Data RSMC Beijing, RSMC Obninsk and RA II Assimilation Systems with 3-D VAR and even some of RSMC Tokyo RSMC Melbourne RA V them 4-D VAR Analysis. These schemes improve the ini­ tial fields starting the forecast runs. Physical NMCs AND CENTRES WITH SIMILAR FUNCTIONS parameterization schemes (such as convection, cloud, and radiation) are constantly improved, leading to bet­ 11. Secondary computers and workstations as well as . ter very-short and short-range predictions, especially mainframes are used in NWP at NMCs. The types of over the tropical regions. Some Centres have started numerical models nm at NMCs are included in Figure 2. experimenting with high-resolution non-hydrostatic A detailed listing of these models, NMCs active in models. Several Centres are now running ensemble-fore­ Numerical Weather Forecasting, and the computer casting systems for medium-range and long-range equipment available is included in Table 2 and Table 3. forecasts (namely Beijing, Bracknell, Montreal, Pretoria, Any NMCs, particularly in Regions 11 and VI, have well­ Tokyo, Washington, ECMWF and INPE (Instituto developed computer capabilities. Many NMCs in RA VI Nacional de Pesquisas Espacias) of Brazil. and 11 run LAMs. While there is still a lack of real-time 16. Significant progress in model development was data-processing capabilities in the NMCs of many devel­ made by the Association of South-East Asian Nations oping countries, satellite-based dissemination systems (ASEAN) Specialized Meteorological Centres (ASMC) in (indicated in Table 2) enable NMCs to receive products Singapore. Emerging Centres, the African Center for directly and reliably from WMCs and RSMCs. Many Meteorological Applications for Development GDPS centres now have Internet access in a non-opera­ (ACMAD), and Drought Monitoring Centres (DMCs) tional and non-real-time mode to selected GDPS Nairobi and Harare made progress. These Centres have products made available by some GDPS centres. plans to further improve their equipment and to train staff at various levels. ACMAD disseminates guidance to VERIFICATION, OF NUMERICAL WEATHER NMCs that is aimed at mec\ium-range forecasting, PREDICTION monthly climate bulletins and experimental seasonal outlooks. ACMAD is also running a Regional Spectral 12. Tbe monthly exchange of verification scores using Model using boundary conditions obtained from the standards and procedures agreed upon by CBS in 1990 data assimilation system of NCEP in Washington, D. C., has continued among the Centres in .Bracknell, United States of America. DMCs Nairobi and Harare pro­ Melbourne, Montreal, Moscow, Offenbach, Washington, vide decadal climate diagnosis information with Tokyo, Toulouse and ECMWF, seasonal outlook for East and Southern Africa. Both 13. A limited set of basic scores is included in the these Centres and ACMAD have started work towards annual Technical Progress Reports on the GDPS. Mean enhancing their climate products in the framework of annual root-mean-square (RMS) errors against observa­ the Climate Information and Prediction Services (CLIPS) tions for 72- and 120-hour ranges for global models are project. plotted in Figure 5 to Figure 16 for the years 1991 to 1997. A small but steady improvement of the scores for LAMs the 500 hPa height can be observed for Asia, Europe and North America areas up to 1996. This is, however, less 17. Fifty GDPS Centres run LAMs operationally and 18 obvious for the Australia/New Zealand area. It is also Centres nm mesoscale models (resolution higher than striking to see that this trend towards improvement 35km). As can be seen in Figure 17, the number of cen­ stopped in 1997, when the models did not do better but tres running mesoscale models has increased perhaps even performed less well, except perhaps for substantially over the decade. (Also noteworthy is that North America. A smaller but still steady improvement global models increased while hemispheric models in scores can be observed in the tropical area, but it decreased in number.) The supply of boundary condi­ seems to have stalled in 1997. tions required for a LAM is handled through bilateral 14.. Monthly scores against analyses from five GDPS arrangements between originating Centres and receiving centres' global models, which include the seasonal Centres, be they WMCs, RSMCs or NMCs, as schemati­ effect, for 500 hPa height and mean sea level pressure for cally shown in Figure 22. Boundary conditions may also 48-, 96- and 144-hour ranges have been compiled by be supplied through the model fielcls disseminated on ECMWF for the years 1992 to mid-1998 (Figures 18 to the GTS, leaving it to each potential user to tailor the 21). Rather small but steady progress can be observed for transmitted data to his particular requirements. THE GLOBAL DATA-PROCESSING SYSTEM V-11

0 W Montreal 9 0 '8 5 llil Montreal ;:a Bracknel! 8 5 WJ Bra~knell 8 0 00 Tokyo 8 0 m Tokyo 7 6 o Toulouaa 7 5 -- D Toulouse 70 • Washington • Washington D ECMWF 70 6 5 5 1::1 ECMWF Ill Melbourne 6 • Melbourne li 6 0 E 60 ~ 5 5 ~ 55 50 5 0 4 5 4 5 ' 4 0 0 ;!-;· r· If- 3 5 5 lF 1r- 0 0 f-- hi 1r 5 5 ' EW .. f-- If- ' .~ ! 0 ~· Elf~H1·1~~ ·.la .• ' £ Lw 1991 1992 1993 1994 1995 1996 1997 0 bi ' ' ·' 1991"=--' 1992 1993 1994 1995 1996 1997 Figure 5 - 72 h 500 hPa Height errors for Asia. Figure 9 - 120 h 500 hPa Height errors for Asia.

90 1!11 Montreal llll Montreal 8 5 5J Bracknell so Gl Bracknell ~ +~~1guse ~ +~~1~use • Washington 70 ~~r!:~ron rJ " e; ECMWf 6 5 • Melbourne 11 Melbourne ! 6 0 ' ! 55 '· ; so 50 - - 45 - 45 ' 40 40 -- '-- 1. 35 35 . . 30 ' 30 ; =- 25 ' ; 25 ' 20 20 H ~ 1991 1992 1993 1994 1995 1996 1997 1991 1992 993 J~t Figure 6- 72 h 500 hPa Height errors for Australia/New Figure 10-120 h 500 hPa Height errors for Australia/New Zealand. Zealand.

9 0 90 ll!l Montreal lill Montreal 8 5 85 '+----- !.'il Bracknel! r.il Bracknell 8 0 80 00 Tokyo .. 5 75 Cl Toulouse 7 ~ t~~f~use 0 70 • Washington 7 ~ ~r!tt~ton [] ECMWF 65 65 11 Melbourne " 6 0 ' 60 ~"Mal~~.!. ' m.·1r- 55 L 5 If- ' If- ' 5 0 ' 50 ' ' 45 4 5 If- 4 0 40 I 1r- I ' n- 35 j)~ if- 1r- I- 1r- 0 l'i---- ' ~~ :: 5 If- I~ 11- ~5 ' 1r- ~~ 0 k ~1991 1992 1993 1994 1995 1996 1997 1991 1994 1995.1am 1996 1997 1992~ Figure 7 - 72 h 500 hPa Height errors for Europe. Figure 11 - 120 h 500 hPa Height errors for Europe.

90 90 1:11 Montreal 11!1 Montreal 85 85 m Bradnell t:iJ Bracknell so 00 Tokyo 80 1>!1! Tokyo 75 ~J Toulouse o Toulouse • Washington 70" • Washington 70 I:J ECMWf D. ECMWF 65 65 ~~ Ill Melbourne 1!1'1 Melbourne ; 60 li" 55 ~ 55 r-- --i ' ' 50 50 . " ' 45 45 kf-- ·~ I' 40 40 tl-- ' -1 ~ 35 • 1- . I'- 3 5 fi-- 30 q 30 ~ ~c-- r- 25 1- 25 r- 1- ~ 1 11- I~ 20 :=m 1991 1994 1995 1996 1997 1991 1992 1993 1994 1995 1996 1997 Figure 8 - 72 h 500 hPa Height errors for North Figure 12- 120 h 500 hPa Height errors for North America. America. V-12 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENTATION

14 14 -- 1!1 Montreol m Montreal 13 13 m Bracknell Gl Bracknell 12 1 2 11 ~ i~~j~use 11 ~ i~~1~use -- • Washington 10 • Washington 10 C:l ECMWF U ECMWF 9 l!il Melbourne 1111 Melbourne 8 ~ 7 ;i' ' 6 ' 5 - - m 4 I~ If­ 3 . If- · If-- 3- '- 2 1f- If- 2 1 1[- If- 1 - - 0 0 1991 1992 1993 1994 1995 1996 1997 19 '92 1993 1994 1996 Figure 13- 72 h 850 hPa Wind errors for the Tropics. Figure IS - 72 h 250 hPa Wind errors for the Tropics.

14 14 m Montreal l:il Montreal 13 l5l Bracknell 13 Q Bracknell 12 ~ ToKyo 12 mTokyo 11 c: Toulouse 11 u Toulouse 10 • Washington 10 • Washington D ECMWF 9 U ECMWF 9 !ill Melbourne ll Melbourn:__ 8 ~ 8 7 i 7 ' 6 6 5 -D 5 4 If- 3 f:: 11- 2 2 1 r- 1 0 !- ~ 0 1991 1992 1993 1994 1995 1996 1997 1991 Figure 14 - 120 h 8SOhPa Wind errors for the Tropics. Figure 16- 120 h 250 hPa Wind errors for the .Tropics.

60

50 "*'~

~ ~ 40 ""·~·"*······:·<''"y-· u~ ·-·-· 0 ...,.IJJOua -~ . i!P"''""''-"'·' ~ ...... Hemispheric lO ---- - .,,~1<" Limited Area "'~ High Resolution Mesoscale z~- .. -----~-·-

20 ,#-~

10 -··- - .... :-~·-····

0 •**~ 90 92 94 95 96 97/98 Year Figure 17- GDPSs running global, hemispheric, limited area and high-resolution mesoscale models.

LONG-RANGE FORECASTS, CLIMATE DIAGNOSTICS seasonal outlooks (e.g., Canada and Japan). A few AND PREDICTIONS Centres are now operationally running coupled ocean­ atmosphere models producing useful long-range 18. Several advanced GDPS Centres are actively forecasts up to seasonal and multi-seasonal prediction engaged in climate diagnosis activities at global, region­ periods, for sea surface temperature and some atmos­ al or national levels. Similarly, the major GDPS Centres, pheric parameters (e.g., ECMWF and National Centres DMC Nairobi, and a few other Centres are actively using for Environmental Prediction (NCEP)). CBS has defined NWP in creating extended-range and long-range fore­ and recommended standards scores to be attached to the casts (including seasonal to inter-annual outlooks). long-range forecast and used for quality assessing. The Ensemble forecasting with truncated models (i.e. core standardized verification system also provides a T63L23) combined with statistical linear regression are means of exchange between GDPS Centres of standard­ the methods used in most of the cases for monthly and ized verification statistics. THE GLOBAL DATA-PROCESSING SYSTEM V-13

=·.wl~=·• DWDOOZT+i44~o·~#">""' NCEPOOZT+OO ... ..::..... UK 12Z T+144 --.. -• EOMWF 12Z T+OO ""''~*""'' NCEPOOZ T+144 --lP-•CANADAOOZ T+96 .. , .... ,. ECMWF 12Z T+144 ~ DWD OOZ T+4a - UK 12Z T+48 "''~-·· CANADAOOZ T+i44 """''~ NOEP ooz T+48 """"'~~ • DWD OOZ T+OO ~ ECMWF 12Z T+4B --.so--· UK 12Z T+96 --CANADA OOZ T+41.1

Figure 18- Northern Hemisphere 500 hPa geopotential height RMS (m) verification against analysis to WMO standards. (Source: ECMWF)

'"''"""'-" DWD OOZ T+144 ""'""W'""• NCEP OOZ T+96 .. ,., .. ,. UK 12Z T+144 ...... , ECMWF 12Z T+96 m·~~o•> NCEPOOZ T+144 --.«o-•CANADAOOZ T+96 .. , ..... ,. ECMWF 12Z T+144:::::::: D~~: ~:: -, -u-, • CANADA OOZ T+144 ""'"~ NCEP OOZ T+4S ~-1'-"-· DWDOOZ T+96 __.,___ ECMWF il'!Z T+48 ...... , UK12Z T+96 ~CANADAOOZT+4S 144 hours

Figure 19 -Northern Hemisphere mean-sea-level pressure RMS error (hPa) verification against analysis to WMO standards. (Source: ECMWF)

""''""'>''•"• DWDOOZ T+144 ""'"''it:'"*' NC'EPOOZ T+96 ... .a .. ,, UK 12Z T+144- ...... ' EOMWF 12Z T+96 o><'"*...,'' NCEPOOZ T+144 _..,Jl!o .. , CANADAOOZ T+96 .. , ..... ,. ECMWF 12Z T+144:::::::: D~~ ~~ ~:: - • <..:r- • • CANADA OOZ T + 144 ,='fk.w,.,...... , NCEP OOZ T + 48 - ~?r ~' DWO OOZ T+96 __,._ ECMWF 12Z T+48 --

Figure 20- Southern Hemisphere 500 hP a geopotential height RMS (m) verification against analysis to WMO standards. (Source: ECMWF)

DWD OOZ T+144 = ~*" ~' NCEP ooz T+96 -·..0-•• UK 12Z T+144 --.. -• ECMWF 12Z T+96 '~·'*I-"'·' NCEP ooz T+144 - -11!'-' CANADA OOZ T+96 -· .. -" ECMWF 12Z T+144:::::::: D~~ ~~ ~:: - , "l(\- , , CANADA OOZ T + 144 ,. __,..~,-~ NCEP OOZ T+ 48 ~ "'

Figure 21 -Southern Hemisphere mean-sea-level pressure RMS error (hPa) verification against analysis to WMO standards. (Source: ECMWF) V-14 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENTATION

World Meteorological run Centres GLOBAL MODELS

Regional Specialized may run GLOBAL MODELS Meteorological Centres ~ Boundary conditions ~ ~ and run LAMs: regional models

National may run Global models Meteorological Centres I ~ Boundary conditions ~ ~ ~ and may run LAMs: regional models, and/or mesoscale models

'I( t apply Pre-and Post-processing of Prediction Data and Statistical Models and Empirical Techniques Figure 22- GDPS showing the supply of boundary conditions for LAMs from global models. CHAPTER VI WORLD WEATHER WATCH DATA MANAGEMENT

WMO DISTRIBUTED DATABASES synoptic features and the data contained in the aero­ nautical codes METAR and SPEC!. CBS approved the 1. The tenth session of CBS (1992) renamed the new alphanumeric code form FM 95 CREX: a Character WWW Distributed Databases concept WMO Distributed form for the Representation and Exchange of data. Databases (DDBs) to more accurately reflect its goals to CREX uses many of the plinciples of BUFR; it also offers meet the requirements to provide data and information flexibility, self-definition and easy expansion. The pri­ needed by WMO and related international programmes, mary goal of CREX will be to avoid the proliferation of but not routinely exchanged on the GTS. A trial of the new alphanumeric codes and additions to existing ones, WMO DDBs concept began in late 1996 and ran for but it will also offer an agreed standard for the visual approximately two years, and these functions have also presentation of data decoded from the BUFR binary been implemented by many centres which did not code. CREX is already used experimentally for the trans­ actively participate in the trial. Many Members are using mission of hydrological data (World Hydrological these services and report that they have found the Observing System (WHYCOS) project), ozone data, radi­ offered data and products have made an important con­ ological data and tide gauge data. CBS has decided to tribution to their operations. Long-range outlooks and allow operational use of CREX to start on 3 May 2000. climate forecasts have been particularly useful to some CBS also approved, for experimental use, Edition 2 of Members. CBS, at its extraordinary session (1998), the WMO binary FM 62 GRIB Code. This new edition, agreed the trial had successfully demonstrated the con­ being object-oriented and modular in its structure, aims cept and further operation of a formal trial was no at satisfying the coding of new grid products generated longer necessary. However, the Commission requested by new techniques such as EPS, long-range forecasting Members to continue to develop DDB services and (seasonal and multi-seasonal outlooks), climate predic­ urged all Members operating DDBs to describe the con­ tion and ensemble wave forecasting (usiiig a coupled tent of their files according to a draft description atmospheric/wave model). It will offer facilities for rep­ standard that has been developed. The draft standard resenting multi-analysis, multi-model ensemble will be provided to the other technical commissions for forecasts, satellite imagery, forecast probability prod­ comment. ucts, vertical cross-sections, Hovmtiller-type diagrams, 2. As a contribution to the WMO DDBs, the multi-dimensional fields and multi-field messages, tra­ Secretariat has made the information contained in jectory and sensitivity forecasts as well as singular Weather Reporting (WMO-No. 9, Volumes A, C and D) vectors and ensemble perturbations. More efficient and in the International list of selected, supplementary and packing schemes will be provided as well as a way to auxiliary ships (WMO-No. 47) available from the WMO indicate small numbers of missing values and a way to Internet server. The contents of the BUFR code tables pack a matrix of values at each grid point (produced by have also been available since November 1998. wave models).

SOFTWARE EXCHANGE THE YEAR 2000 PROBLEM

3. Exchange of software between Members has been 5. Noting Resolution 5 (EC-XLIX) regarding the Year facilitated through the CBS Software Registry, which 2000 Problem, a number of actions have been taken to provides information on software available from and minimize the impact of this issue on the operation of requested by Members. A digital version of the registry WWW. WMO sent letters to manufacturers of meteoro­ is maintained and has been available via the WMO logical equipment to gather information, and circular Internet server since late 1995. Since its inception, the letters to all Members in July 1997 and May 1998 which on-line registry has been accessed an average of 280 provided information on the problem, and asked times per month. Members to inform the Secretariat of their plans for ensuring that their systems are Year 2000 compliant. DATA REPRESENTATION FORMS WMO has posted information and advice on the WMO Internet server and has ensured the issue was discussed 4. The years 1997 and 1998 were marked by impor­ at numerous meetings over the past two years. WMO tant developments in WMO data representation. The conducted special sessions dedicated to this topic at expansion of table-driven data representation forms has three meetings and eo-sponsored three Year 2000 continued. New types of data, especially those produced Workshops (Bracknell, Prague and Honolulu) during by satellites, can now be coded in BUFR, as well as the 1998. VI-2 WORLD WEATHER WATCH -NINETEENTH STATUS REPORT ON IMPLEMENTATION

6. As of 1 December 1998, responses from 61 manu­ scale, and that these changes were expected to facturers and 114 Members had been received regarding continue and could even accelerate over the next few Year 2000 compliance. Of these Members, 11 reported years. The Commission tasked a new Open Programme were compliant, 82 reported they had projects underway Area Group on Information Systems and Services to to ensure compliance, and 15 provided no information determine how to make most effective use of the on their status. Fifteen RTHs reported they were compli­ Internet. ant, and all of the remaining RTHs indicated they had 8. Many NMHSs connected to the Internet over the projects underway to ensure compliance. past few years. The results of a survey on connectivity conducted in late 1998 are shown in Figures 1 to 3. IMPACT OF THE INTERNET Based on the 145 replies received, 137 NMHSs (95 per cent) have connections to the Internet. Of the eight 7. CBS noted that the Internet has undergone NMHSs that said they did not have connections, four rapid evolution of coverage and capacity on a global plan to be connected within six months.

Internet E-mail FTP site Web slte No Unknown Connection Connection Figure 1 -Type of Internet capability for NMHS. Figure 2 -Speed of NMHSs' Internet connections.

100 90 80 .:<; 70 ~ 60 ~ 0 50 ~0 40 ~ " 30 ~ "'- 20 10 0 Region I Region 11 Region Ill I Region IV Region V Region VI .Connected (J No connection [I Unknown (no reply)

Figure 3 - Internet connectivity by Region. ANNEX I SUMMARY OF THE RESULTS OF THE ANNUAL GLOBAL MONITORING OF THE OPERATION OF THE WORLD WEATHER WATCH (WWW) CARRIED OUT FROM 1 TO 15 OCTOBER 1998

STATUS OF THE DATA AVAILABILITY ON THE GTS For TEMP - this number varies little from chapter 3 Table 1 under "Required in the 1. The non-real-time annual global monitoring is RBSN". carried out to check the availability of meteorological Required obs: The number of Required Reports or data foreseen for global exchange. The datasets moni­ observations is the number of required tored include SYNOP, TEMP, PILOT, CLIMAT and CLIMAT stations times four for TEMP and times TEMP reports from RBSN stations. The results of the two for SYNOP. 1998 annual global monitoring are summarized in the %Rec/Req: The number of reports received expressed Annual Global Monitoring Report available from as a percentage of Required Reports. WWW. Excerpts are reported here. %Rec/Exp: The number of reports received expressed 2. The monitoring covers stations defined in the as a percentage of Expected Reports. RBSN as committed to by Members in Weather Reporting 4. The comparison of the results of the 1998 annual (WMO-No. 9, Volume A). Members may send changes monitoring of SYNOP to those of previous years at the and updates to the information contained in Volume A regional level shows particularly: viae-mail, through the WMO Internet server, or by post. (a) The percentage of Required Reports received has been about the same throughout the last decade SYNOP AND TEMP OBSERVATIONS AVAILABILITY for each Region, with highs above 80 per cent for 1991 TO 1998 Regions 11, IV and VI, and lows around SO per cent for Regions I, Ill and V. 3. The availability of SYNOP reports is shown in (b) The percentage of Required Reports received from Table 1 and Figure 1. The availability of part A of TEMP Region V declined in 1996. Because many stations reports is shown in Table 2 and Figure 1. report at hours offset from the main synoptic An explanation of terms is in order: times, which were not counted as of the 1996 Received obs: The average number of reports received monitoring, the percentage dropped. A quick look daily on the MTN of the GTS; for at Table 1 shows that the percentage of Expected SYNOP at the main synoptic observa­ Reports received remained steady at about 83 per tion hours of 0000, 0600, 1200 and cent during the decade. 1800 UTC, and for TEMP at 0000 and (c) The number of Expected Reports dropped in 1200 UTC. Regions I, 11, VI and V, and rose in Regions Ill and Expected obs: The number of reports made daily VI. In the latter two Regions stations were according to Volume A. added to the RBSN. In Regions IV and VI, the per­ For SYNOP - at any of the main synoptic hours of centage of Expected Reports rose to nearly 0000, 0600, 1200 and 1800 UTC. (This 100 per cent. Both the numbers of Required counts all the stations in the RBSN even Stations and Expected Reports rose in Region VI, if it observes at only one of these hours. giving it the highest percentages of received The reader may refer to Chapter 3 Table reports globally. 1 to see the number of stations expected 5. The comparison of the results of the 1998 annual to report every three hours and less fre­ monitoring of TEMP to those of previous years at the quently.) regional level shows particularly: For TEMP- at 0000 or 1200 UTC. (The reader may (a) The percentage of Required Reports received and refer to Chapter 3 Table 3 to see the num­ Expected Reports received has been about the ber of stations expected to report twice a same in Regions I and V, has risen in Regions Ill day and less frequently.) and IV and has fallen in Regions 11 and VI over the Required stns: The number of surface stations in the last decade. RBSN as committed to by Members as (b) Less than SO per cent of Required Reports and per Weather Reporting (WMO-No. 9, about 60 per cent of Expected Reports were Volume A). received from Regions I and Ill. For SYNOP - this is required stations minus the (c) Overall, globally, there has been a reduction in ocean stations, which are not counted in Required Reports received from 66 per cent to 59 the Annual Global Monitoring as they per cent since 1991. The percentage of Expected do not record SYNOP code. Thus this Reports received has declined from 83 per cent to number differs marginally from the fig­ 76 per cent. Globally, nearly half the TEMP ure in Chapter 3 Table 1 under reports were not received in the 1998 monitoring 1'required 11 stations. period. AI-2 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENTATION

Table 1 RBSN SYNOP October monitoring report for 1991 to 1998. The number of required stations, the number of required observations (four observations per day per station), the number of expected observations, and an average number of reports actually received daily are shown.

RBSN SYNOP reports

1991 1992 1993 1994 1995 1996 1997 1998

Region I Received obs 901 1243 1253 1241 1102 1125 1127 1245 Expected obs 2242 2241 2225 2222 2085 2080 2087 2078 Required stns 721 699 699 699 621 621 621 621 Required obs 2884 2796 2796 2796 2484 2484 2484 2484 %Rec/Req 31.2% 44.5% 44.8% 44.4% 44.4% 45.3% 45.4% 50.1% %Rec/Exp 40.2% 55.5% 56.3% 55.9% 52.9% 54.1% 54.0% 59.9%

Region li Received obs 3747 3774 3857 3844 3661 3859 3694 3763 Expected obs 4565 4540 4484 4472 4469 4584 4612 4528 Required stns 1174 1174 1163 1163 1161 1188 1195 1195 Required obs 4696 4696 4652 4652 4644 4752 4780 4780 %Rec/Req 79.8% 80.4% 82.9% 82.6% 78.8% 81.2% 77.3% 78.7% %Rec/Exp 82.1% 83.1% 86.0% 86.0% 81.9% 84.2% 80.1% 83.1%

Region II1 Received obs 678 616 671 914 926 829 966 lOOS Expected obs 1097 1032 1025 1315 1379 1366 1372 1418 Required stns 338 338 338 436 434 436 435 467 Required obs 1352 1352 1352 1744 1736 1744 1740 1868 %Rec/Req 50.1% 45.6% 49.6% 52.4% 53.3% 47.5% 55.5% 53.8% %Rec/Exp 61.8% 59.7% 65.5% 69.5% 67.2% 60.7% 70.4% 70.9%

Region IV Received obs 1428 1645 1698 1679 1657 1647 1606 1724 Expected obs 1976 1992 2I39 2111 2111 2106 1857 1728 Required stns 572 572 584 584 584 582 514 514 Required obs 2288 2288 2336 2336 2336 2328 2056 2056 o/oRec/Req 62.4% 71.9% 72.7% 71.9% 70.9% 70.7% 78.1% 83.9% %Rec/Exp 72.3% 82.6% 79.4% 79.5% 78.5% 78.2% 86.5% 99.8%

Region V Received obs 1059 994 1052 1188 1171 832 805 857 ExpeCted obs 1253 1222 1225 1383 1423 1027" 1036 1033 Required stns 362 359 359 407 407 406 411 411 Required obs 1448 1436 1436 1628 1628 1624 1644 1644 %Rec/Req 73.1% 69.2% 73.3% 73.0% 71.9% 51.2% 49.0% 52.1 o/o o/oRec/Exp 84.5% 81.3% 85.9% 85.9% 82.3% 81.0% 77.7% 83.0%

Region VI Received obs 3070 3037 3052 2328 2418 2466 2426 2688 Expected obs 3290 3264 3238 2605 2614 2675 2684 2710 Required stns 843 843 842 664 677 682 682 714 Required obs 3372 3372 3368 2656 2708 2728 2728 2856 %Rec/Req 91.0% 90.1% 90.6% 87.7% 89.3% 90.4% 88.9% 94.1% %Rec/Exp 93.3% 93.0% 94.3% 89.4% 92.5% 92.2% 90.4% 99.2%

Total Received obs 10883 11309 11583 11194 10935 10758 10624 11282 ExpeCted obs 14423 14291 14336 14108 14081 13838 13648 13495 Required stns 4010 3985 3985 3953 3884 3915 3858 3922 Required obs 16040 15940 15940 15812 15536 15660 15432 15688 %Rec/Req 67.8% 70.9% 72.7% 70.8% 70.4% 68.7% 68.8% 71.9% %Rec/Exp 75.5% 79.1% 80.8% 79.3% 77.7% 77.7% 77.8% 83.6% -

SYNOP AND TEMP STATION PLOTS FOR 1 TO 15 from 2 155 stations, or about half of the required sta­ OCTOBER1998 MONITORING PERIOD tions in the RBSN. At least half of the Required Reports were received from 3 076 (2 155 + 921) or three-quarters 6. A quick glance at Figure 3 shows the areas of the of the Required Stations. There were 555 "silent" or non­ world from which many SYNOP observations are operational stations during the 1998 monitoring period. received (dark areas) and few observations are received By way of comparison, 592 stations were silent in 1997 (lighter areas) at the main synoptic hours. In the and 621 were silent in 1996. Southern Hemisphere there are more light areas than 7. Figure 4 shows that darker areas of the map, areas dark. Figure 3 shows the stations from which reports from which at least 90 per cent of the TEMP Required were received at threshold values of 50 per cent and 90 Reports were received, are highly concentrated in North per cent. At least 90 per cent of reports were received America, Europe and East Asia. No reports were received ANNEX I AI-3 Table 2 RBSN TEMP October monitoring report for 1991 to 1998. The number of required stations, the number of required observations (two observations per day per station), the number of expected reports as committed to by Members per Weather Reporting (WMO-No. 9, Volume A), and an average number of reports actually received daily are shown. RBSN TEMP reports

1991 1992 1993 1994 1995 1996 1997 1998

Region I Received obs 40 52 53 48 58 60 64 54 Expected obs 90 91 93 93 104 103 101 92 Required stns 98 99 99 99 101 101 101 101 Required obs 196 198 198 198 202 202 202 202 %Rec/Req 20.4% 26.3% 26.8% 24.2% 28.7% 29.7% 31.7% 26.7% %Rec/Exp 44.4% 57.1% 57.0% 51.6% 55.8% 58.3% 63.4% 58.7%

Region 11 Received obs 500 485 487 477 469 406 427 389 Expected obs 585 588 598 590 586 566 581 576 Required stns 324 324 334 334 334 324 326 326 Required obs 648 648 668 668 668 648 652 652 %Rec/Req 77.2% 74.8% 72.9% 71.4% 70.2% 62.7% 65.5% 59.7% %Rec/Exp 85.5% 82.5% 81.4% 80.8% 80.0% 71.7% 73.5% 67.5%

Region Ill Received obs 33 33 31 36 33 22 27 39 Expected obs 59 55 54 53 59 56 54 57 Required stns 59 59 59 52 52 52 52 56 Required obs 118 118 118 104 104 104 104 112 %Rec/Req 28.0% 28.0% 26.3% 34.6% 31.7% 21.2% 26.0% 34.8% %Rec/Exp 55.9% 60.0% 57.4% 67.9% 55.9% 39.3% 50.0% 68.4%

Region IV Received obs 243 247 253 229 247 247 243 238 Expected obs 277 273 275 275 268 271 257 255 Required stns 152 153 !50 151 151 149 142 142 Required obs 304 306 300 302 302 298 284 284 %Rec/Req 79.9% 80.7% 84.3% 75.8% 81.8% 82.9% 85.6% 83.8% %Rec/Exp 87.7% 90.5% 92.0% 83.3% 92.2% 91.1% 94.6% 93.3%

Region V Received obs 107 104 102 103 104 106 109 101 Expected obs 126 125 119 120 119 110 121 121 Required stns 102 100 lOO 96 96 96 97 97 Required obs 204 200 200 192 192 192 194 194 %Rec/Req 52.5% 52.0% 51.0% 53.6% 54.2% 55.2% 56.2% 52.1% %Rec/Exp 84.9% 83.2% 85.7% 85.8% 87.4% 96.4% 90.1% 83.5%

Region VI Received obs 230 224 206 230 220 198 203 205 Expected obs 249 259 261 279 279 276 273 262 Required stns 140 142 142 168 151 149 149 142 Required obs 280 284 284 336 302 298 298 284 %Rec/Req 82.1% 78.9% 72.5% 68.5% 72.8% 66.4% 68.1% 72.2% %Rec/Exp 92.4% 86.5% 78.9% 82.4% 78.9% 71.7% 74.4% 78.2%

Total Received obs 1153 1145 1132 1123 1131 1039 1073 1026 Expected obs 1386 1391 1400 1410 1415 1382 1387 1363 Required stns 875 877 884 900 885 871 867 864 Required obs 1750 1754 1768 1800 1770 1742 1734 1728 %Rec/Req 65.9% 65.3% 64.0% 62.4% 63.9% 59.6% 61.9% 59.4% %Rec/Exp 83.2% 82.3% 80.9% 79,6% 79.9% 75.2% 77.4% 75.3% from almost one quarter (197 stations) of the required 60 to 70 degrees north and 50 to 150 degrees east. A stations. This compares to 184 stations in 1997 and 190 good increase in observations received from South in 1996. Most of Africa and large areas of South America America is also noteworthy. have silent stations.

SYNOP AND TEMP MONITORING BY 10-DEGREE 9. Referring to Figure 6, there was relatively little SQUARES change in the reports received between 1996 and 1998 over most of the world. There was a reduction in reports 8. Referring to Figure 8, fewer observations were received in western South America and a gain in eastern received in 1998 than in 1996 significantly in the area of South America. Al-4 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENTATION 1 OO.Oo/o ..... 90.0o/o ~ • • • • • • . ..¥ 80.0o/o --- ~ 70.0o/o ~ ~ ------

..:o;:-,-, :0" ~ - ---- ~ -~--~-~~-- ·;;; 60.0o/o - ---~~I A. ~ 0 0.. SO.Oo/o - -*lVI~~~~~. V " "*"vi 0\ ~ ~ ro " 40.0o/o ...... ~J ~ ·-- c ~ V ... ~ 30.0o/o

0.." 20.0o/o ~ 1 O.Oo/o O.Oo/o 1991 1992 1993 1994 1995 1996 1997 1998 October Monitoring Period

Figure I - RBSN SYNOP Observations actually received for 1991 to 1998 shown as a percentage of the total required in the RBSN.

90.0% .>..L ...l.L ., 80.0% -~ r---t ~ ...... ~ - c-- ~- - - ... 70.0% --.- -....;;::::

f-~ --·------<11 60.0% --- - :0 ~lE )I( liE - ;[( m ~e-o - •... ~------~" - '§ 50.0% liE c.. ""' _____ , _____ ------~ ~- ::::,1 F 4o.o% ~lVi ~ c ..... "'*"' V I ~ 30.0% - .... ------~ ,.,._VI' <11 ~ ~ -. c.. 20.0% ------

10.0% ~ ------" ....

0.0% ;-- ~.,.- ~- 1991 1992 1993 1994 1995 1996 1997 1998 October Monitoring Period

Figure 2- RBSN TEMP Observations actually received for 1991 to 1998 shown as a percentage of the total possible from the required stations in the RBSN. ANNEX I AI-5

Percentage of reports based on main sypnotic hours • >90 to 100% (2 155) Q 50 to 90% (921) o d to 50% (379) V silent sat!ons (555) Figure 3 -Availability of SYNOP reports from RBSN Station during the I to IS October 1998 monitoring period. The percentage of reports received is based on the main synoptic hours, 0000, 0600, 1200, and 1800 UTC. The number of stations from which more than 50 per cent and 90 per cent of reports was received is indicated. Silent stations are also indicated.

Percentage of reports based on main sypnotic hours • >90 to 100% (396) e 50 to 90% (152) o <1 to 50% {146) V silent sat!ons {197)

Figure 4- Availability of TEMP reports from RBSN Stations during the I to IS October 1998 monitoring period. The percentage of reports received is based on Part A for 0000 and 1200 UTC. The number of stations from which more than SO per cent and 90 per cent of reports was received is indicated. Silent stations are also indicated. Al-6 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENTATION

600N

180" 160'W 140'W 1lO'W 100'W 80'W 60'W 40'W 20'W 0" 20"E 40'E 60'E 80'E lOO"E 120"E 140'E 160"E 180' Figure 5 - SYNOP reports received within six hours of observation time at MTN centres from RBSN stations during the 1 to 15 October 1998 monitoring period. Data are expressed as a percentage of the observations necessary to satisfy a resolution of 250 kilometres in each 10-degree by 10-degree block.

180" 160'W 140"W 120'W 100'W BCf'W 60'W 40'W 20'W 0' Figure 6- Differences between the percentages of SYNOP reports received during the 1996 and 1998 monitoring periods.

TIMELINESS OF DATA AVAILABILITY ON THE GTS (a) About 72 per cent of the SYNOP reports and 59 per cent of the TEMP reports expected from the 10. As regards timeliness in receiving observational RBSNs were available at MTN centres; data, the availability of SYNOP and Parts A of TEMP (b) Sixty-seven per cent of the SYNOP reports were reports within specified hours after observation received within one hour after the observation time, times is shown in Table 3 and Table 4. It can be noted and an additional 5 per cent were received between that: one hour and six hours after the observation time; ANNEX I Al-7

60'N 60'N

40'N 40'N

20'N 20'N

EQ EQ

20'S 20"5

40'5 40"5

180" 160'W 140'W 120"W 100'W 80'W 60'W 40'W 20'W 0' Figure 7 -TEMP reports received within 12 hours of observation time at MTN centres from RBSN stations during the 1 to 15 October 1998 monitoring period. Data are expressed as a percentage of the observations necessary to satisfy a resolution of 550 kilometres in each 10-degree by 10-degree block.

60'N 60'N

40'N

20'N

EQ

20"5

40'S

60'5

180" 16o"W 140'W 12o•w 1oo·w so•w 60'W 40''W zo•w 0" Figure 8-Differences between the percentages of TEMP reports received during the 1996 and 1998 monitoring periods.

(c) Globally, 53 per cent of the TEMP reports were from Region VI were more than 90 per cent of received within two hours after the observation SYNOP reports received within 6 hours; time, an additional 6 per cent were received (e) In Region Ill, significantly more TEMP observations between two hours and 12 hours after the obser­ made at 1200 UTC are received than those made at vation time, nearly half the TEMP reports were not 0000 UTC, while the opposite is true for Region V; and received after two hours, and 41 percent were not (f) The global availability of SYNOP and TEMP received after 12 hours. reports six and 12 hours after observation time (d) The availability of SYNOP and TEMP reports was not significantly different between 1996, 1998 remains relatively low, in particular in Region I (50 and previous years (SYNOP- 69 per cent in 1996, per cent and 27 per cent at six and 12 hours, 72 per cent in 1998; TEMP- 60 per cent in 1996, respectively, after observations time), and only 59 per cent in 1998). AI-8 WORLD WEATHER WATCH- NINETEEI\TH STATUS REPORT ON IMPLEMENTATION Table 3 Timeliness of reception of SYNOP reports at MTN centres during the annual global monitoring period 1 to 15 October 1998.

Percentage of SYNOP reports received Number of WMO stations Observation: 0000 UTC Observation: 0600 UTC Observation: 1200-UTC Observation: 1800 UTC Total Region comprising Received within Received within Received within Received within Received within the RBSN 1h 2h 6h 1h 2h 6h 1 h 2h 6h 1h Zh 6h 1h 2h 6h Region I 621 29 31 37 47 54 58 48 ss 56 45 48 49 42 47 so Region 11 1195 74 76 79 77 79 80 78 79 80 72 74 76 75 77 79 Region Ill 467 48 52 53 21 22 23 61 67 71 64 66 68 48 52 54 Region IV 514 83 83 84 77 78 78 84 85 86 87 88 88 83 83 84 Region V 411 72 80 81 72 79 80 65 70 71 ss 61 66 45 so 52 Region VI 714 87 88 90 94 95 95 94 96 96 94 95 9S 92 94 94 Antarctic 88 41 58 64 29 37 58 39 57 64 44 61 63 38 53 62 Total 4010 67 69 72 67 70 72 73 76 78 70 73 74 67 70 72

Table 4 Timeliness of reception of TEMP reports at MTN centres during the annual global monitoring period 1 to 15 October 1998.

Percentage of TEMP reports received Number of WMO stations Observation: 0000 VTC Observation: 1200 UTC Total Region comprising Received within Received within Received within the KBSN 2h l2h Zh '12h 2h 12h ..... Region 1 101 20 24 25 30 23 27 Region II 326 52 63 49 56 50 60 · Region Ill 56 18 20 36 50 27 35 Region .IV 142 80 80 86 87 83 83 Re_gion V 97 57 70 26 34 42 5.2 Reg-ion VI 142 76 79 63 bS 70 72 Antarctic 14 53 61 35 51 44 56 Global 878 55 62 51 57 53 59

Table 5 Number of stations included in RBSNs from which no SYNOP or TEMP (Part A) reports were received at MTN centres during the global monitoring period 1 to 15 October 1998.

SYNOP TEMP (Part A) WMOReglon Silent stations Silent stations Silent stations Silent stations included but included but in the implemented in the Implemented RBSN (ref. Volume A) RBSN (ref. Volume A) (requi,.d) (expected) (required) (expected)

Re.gion I 160 133 60 30 Region 11 121 107 71 51 Region Ill 52 47 22 13 Region IV 28 25 11 7 Region V 159 30 21 7 Region VI 14 11 10 9 Antarctic 21 19 2 2 Total 555 372 197 119 - ANNEX I AI-9

11. The numbers of "silent stations" - stations OTHER MTN MONITORING (1 TO 15 OCTOBER 1998) from which no reports were received at MTN centres - are given in Table 5. The corresponding missing 12. In the two-week monitoring period, MTN centres reports represent a significant part of the total missing received 1 316 CLJMAT and 424 CLJMAT TEMP reports, or reports: 36 per cent and 48 per cent, respectively, of the total num­ (a) 555 stations or 14 per cent were silent for SYNOP ber of reports which were expected from RBSN stations. reports required from RBSNs, down from 621 in 13. MTN centres that participated in the special MTN 1996; and monitoring reported to have received on average per day during the monitoring period: (b) 197 stations or 22 per cent were silent stations for 2 560 SHIP reports for main standard hours Parts A of TEMP reports required from RBSNs com­ 6 900 BUOY reports pared to 190 in 1996. 4 5 70 aircraft weather reports (AIREP) 12 100 AMDAR reports

ANNEXII WWW OPERATIONAL INFORMATION SERVICE (OIS)

1. The purpose of the Operational Information broadcasts, port services and the lNMARSAT Cost Earth Service (OIS) is to collect from and distribute to WMO Stations; supplements are published bimonthly. _Members up-to-date information on observing statics and programmes, facilities, services and products of International Llst of Selected, Supplemen­ WWW. OIS publishes information in printed form, on tary and Auxiliary Ships (WMO-No. 47) computer diskettes and, most recently, on WMO's Catalogue of about 7000 mobile ships participat- Internet server, where it can be accessed via the World ing in the WMO VOS scheme providing details of Wide Web (http://www.wmo.ch) and FTP vessels and their routes, and technical information on (ftp://www.wmo.ch) for accessing and updating infor­ meteorological equipment and methods used on board, mation. including exposure, location and instrument 2. The operational infonnation is organized as fol- height/depth. Soft updates are issued quarterly and a lows: new edition is published annually. Weather Reporting (WMO-No. 9) Volume A - Observing Stations Regional Basic Synoptic Networks (RBSNs) Catalogue of 10 000 surface stations and 950 The list of observing stations comprising the upper-air stations of GOS land stations and Fixed Ship RBSNs adopted by each WMO Region are published and Stations (FSS), published twice a year. updated regularly. The updated lists are available on Volume B - Data-processing diskette and on the Internet server. Catalogue of the output products available from GDPS centres including area coverage and availability, Monthly Operational Newsletter on the production means, formats for transmission over the Operation of the WWW and Marine GTS, processing time, grid systems, etc., update supple­ Meteorological Services (MMS) ments are published twice a year. The newsletter provides a summary of recent Volume C- Transmissions operational changes and notifications concerning GOS, Catalogue of meteorological bulletins transmitted GTS, GDPS and the MMS Programme; a special annex is on the GTS containing approximately 20 000 abbreviat­ devoted to codes. The newsletter is also made available ed headings, 10 000 of which refer to products in the on WMO's World Wide Web and FTP servers. GRID or GRIB codes; new editions are published twice a year. METNO and WIFMA telegraphic messages Volume D - Information for Shipping The weekly METNO (meteorological) and WIFMA Catalogue of meteorological assistance available (marine) notifications transmitted on the GTS carry the to marine users including coastal radio stations and most up-to-date information on operational changes.

ANNEX Ill ACRONYMS

ACARS Aircraft Communication Addressing and Reporting System A!REP aircraft weather report AMDAR aircraft meteorological data acquisition and relay APT automatic picture transmission ASDAR aircraft to satellite data acquisition and relay ASEAN Association of South-East Asian Nations ASECNA Agency for Air Safety in Africa and Madagascar ASMC ASEAN Specialized Meteorological Centre

CBS Commission for Basic Systems CGMS Coordination Grove for Meteorlogical Satellites CLIPS Climate Information and Prediction Services CNES Centre national d'etudes spatiales COLA Center for Ocean-Land-Atmosphere Interactions CPTEC Centro de Previsao do Tempo e Estudos Climaticos

DBCP Drifting Buoy Cooperation Panel DCS data collection system DDB Distributed Databases DMC Drought Monitoring Centre DMSP Defense Meteorological Satellite Programme

ECMWF European Centre for Medium-Range Weather Forecasts EM WIN Emergency Managers Weather Information Network EPS Ensemble Prediction Service EUMETSAT European Organization for the Exploitation of Meteorological Satellites

FAO Food and Agriculture Organization of the United Nations

GAW Global Atmosphere Watch GCOS Global Climate Observing System GDPS Global Data-processing System GMDSS Global Maritime Distress and Safety System GMS geostationary meteorological satellite GOES geostationary operational environmental satellite GOS Global Observing System GSN GCOS Surface Network GTOS Global Terrestrial Observing System GTS Global Telecommunication System GUAN GCOS Upper-Air Network

HF High frequency HIRLAM High resolution limited area model HR High resolution HRPT High resolution picture transmission

!AEA International Atomic Energy Agency ICAO International Civil Aviation Organization IGOSS Integrated Global Ocean Services System !MOP Instruments and Methods of Observation Programme Alll-2 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENTATION

INMARSAT International Maritime Satellite System IOC Intergovernmental Oceanic Commission IS CS International Satellite Communications System !TU International Telecommunication Union

LAM limited area model

MDD Meteorological Data Distribution METEOSAT EUMETSAT series of meteorological geostationary satellites MMAOAP Marine Meteorology and Associated Oceanographic Activities Programme MTN main telecommunication network

NMC National Meteorological Centre --~MHS national Meteorological and Hydrological Service NMS national Meteorological Service NMTN National Meteorological Telecommunication network NOAA National Oceanic and Atmospheric Administration NWP numerical weather prediction

OM Ombrometer

PWS Public Weather Services

RA regional association RBSN Regional Basic Synoptic Network RMDCN Regional Meteorological Data Communication Network RMS root-mean-square RMTN Regional Meteorological Telecommunication Network RSMC Regional Specialized Meteorological Centre RTH Regiojlal Telecommunication Hub

SADC ~outhern African Development Community SSA WWW System Support Activity SYNOP Report of surface observation from a land station

TCP Tropical Cyclone Programme TEMP Upper-level temperature, humidity and wind report from a land station

UKSF UK satellite facilities UNEP United Nations Environment Programme

VSAT very small aperture terminal

WAFS World Area Forecast System WDM WWW Data Management WEFAX weather facsimile WHO World Health Organization WHY COS World Hydrological Cycle Observing System WMC World Meteorological Centre WMO World Meteorological Organization WRC World Radiocommunication Conference www World Weather Watch ANNEX IV REFERENCES

The 1998 Annual Global Monitoring of the Implementation of the WWW

Guide on meteorological observation and information distribution systems at aerodromes (WMO-No. 731)

Guide on the automation of data-processing centres (WMO-No. 636)

Guide on the Global Data-processing System (WMO-No. 305)

Guide on the Global Observing System (WMO-No. 488)

Guide on World Weather Watch data management (WMO-No. 788)

Guide to agricultural meteorological practices (WMO-No. 134)

Guide to climatological practices (WMO-No. 100)

Guide to hydrological practices (WMO-No. 168)

Guide to marine meteorological services (WMO-No. 471)

Guide to meteorological instruments and methods of observation (WMO-No. 8)

Guide to moored buoys and other ocean data acquisition systems (WMO-No. 750)

Guide to practices for meteorological offices serving aviation (WMO-No. 732)

Guide to public weather services practices (WMO-No. 834)

Guide to qualifications and training of meteorological personnel employed in the provision of meteorological services for inter­ national air navigation (WMO-No. 114)

Guide to the applications of marine climatology (WMO-No. 781)

Guide to the provision of meteorological service for international helicopter operations (WMO-No. 842)

Guide to wave analysis and forecasting (WMO-No. 702)

International list of selected, supplementary and auxiliary ships (WMO-No. 47)

Manual on the Global Data-processing System (WMO-No. 485)

Manual on the Global Observing System (WMO-No. 544)

Manual on the Global Telecommunication System (WMO-No. 386)

Manual on codes (WMO-No. 306)

Report of the Adequacy of the Global Climate Observing Systems; United Nations Framework Convention on Climate Change; November 2--13, 1998; Buenos Aires, Argentina (GCOS, October 1998) AIV-'2 WORLD WEATHER WATCH- NINETEENTH STATUS REPORT ON IMPLEMENTATION

Weather reporting (WMO-No. 9)

WMO Long-term Plan: Overall policy and strategy 1996-2005- Fourth WMO Long-term Plan, Part I (WMO-No. 830)

The World Weather Watch Programme 1996-2005: Fourth WMO Long-term Plan, Part II: Volume 1 (WMO/TD-No. 700)

WWW Technical Progress Report on the Global Data-processing System: 1991 (V)'MO/TD-No. 491)

WWW Technical Progress Report on the Global Data-processing System: 1992 (WMO/TD-No. 495)

WWW Technical Progress Report on the Global Data-processing System: 1993 (WMO/TD-No. 608)

WWW Technical Progress Report on the Global Data-processing System: 1994 (WMO/TD-No. 662)

WWW Technical Progress Report on the Global Data-processing System: 1995 (WMO/TD-No. 744)

WWW Technical Progress Report on the Global Data-processing System: 1996 (WMO/TD-No. 807)

WWW Technical Progress Report on the Global Data-processing System: 1997 (WMO/TD-No. 896)