FFOORREECCAASSTT DDEEMMOONNSSTTAARRTTIIOONN PPRROOJJEECCTT ((CCYYCCLLOONNEE)) -- 22001100 (INTENSE OBSERVATION PERIOD : 05 -08 NOV 2010) REPORT BY FIELD OPERATIONAL CENTRE by Y.E.A.RAJ, S.BALACHANDRAN, RM.A.N.RAMANATHAN, B.GEETHA, K.RAMESH, N.SELVAM M.V.GUHAN & D.RAJAN BABU Cyclone Warning & Research Centre Regional Meteorological Centre, Chennai i PREFACE India, having an extensive coastline is subjected to the fury of landfalling Tropical Cyclones (TC) that form over the North Indian Ocean (NIO) during the pre-monsoon months of April-May and the Northeast monsoon season of October-December, which is the chief cyclone season over the NIO. As such, prediction of TC genesis, movement and intensity is a very important mandate of India Meteorological Department (IMD). With the ushering in of modern observing systems and remote sensing techniques through satellites, huge volumes of meteorological data over the erstwhile data sparse oceanic areas are now available. Assimilation of such data into the Numerical Weather Prediction (NWP) models have improved TC forecasting leaps and bounds in the developed countries in the recent decades. Now, India is also striving hard to collect crucial data from TC fields and assimilate them in NWP models to improve its forecasts on TC genesis, movement, intensity and landfall. As an outcome of Indo-US atmospheric science programme, a scientific plan namely Forecast Demonstration Project (FDP) (Cyclone) – was designed with key scientific objectives of demonstrating the ability of the NWP models to predict cyclone track, intensity and landfall over the Bay of Bengal using enhanced observation including the measurements from dropsonde over the periphery of the cyclone and to assess the accuracy limits of the forecasting aspects related to cyclone. The FDP is a multi institutional programme involving many related scientific institutions. It is conducted in three phases - Pre-Pilot phase (15 October – 30 November, 2008), Pilot phase – (15 October – 30 November, 2009) and Field Phase (15 October – November, 2010-2011). For implementation of this programme, National Operational Centre (NOC) was established at Northern Hemispheric Analysis Centre (NHAC), IMD New Delhi which is responsible for entire coordination and declaration of Intense Observation Periods (IOPs). Also, the Cyclone Warning & Research Centre, functioning at RMC Chennai, was made as Field Operational Centre (FOC) to establish links with FDP partners, to notify IOP phases to field ii stations and other FDP partners, to coordinate and update the status of observation and to collect and transmit informations received from the field stations and FDP partners to the NOC. Being a centre dedicated for studies on TCs, CWRC, RMC Chennai is aptly functioning as the FOC and is actively involved in coordinating with the field stations, including making arrangments for taking special GPS sonde ascents and setting onboard equipments in the Sagar Kanya Cruise during IOPs. During the pre-pilot and pilot phases of the programme, the FOC, Chennai archived all raw data collected, including special observations taken during IOPs, in a CD, and sent to the NOC. Now, for the field phase of the programme (15 October – 30 November 2010), during which one IOP was observed in connection with formation and movement of Severe Cyclonic Storm ‘Jal’ over the Bay of Bengal during 05-08 November 2010, this centre is bringing out a Weather Summary of observations and analysis on a regional scale, which, I hope, would be immensely useful to the various FDP research groups. iii Acknowledgements CWRC, RMC Chennai is grateful to IMD, HQ for designating it as the FOC for the FDP programme. The Weather Summary of FDP, IOP, 05-08 November 2010 is an outcome of efforts of many personnel involved in generating crucial data for prosecuting advanced studies on tropical cyclones. Special observations were taken during the cyclone period by all participating institutions, IMD field stations in coastal Tamil Nadu and Andhra Pradesh and Sagar Kanya Cruise members. Our deep felt thanks to our FDP partners Indian Space Research Organisation, National Atmospheric Research Laboratory, Tirupati, INS Rajali, Arakkonam for their valuable observations during the IOP. The FOC, Chennai also acknowledges the crucial role played by the IMD observers at the field stations for taking special hourly observations continuously for three days in bad weather conditions despite manpower shortage. Our special thanks are due to those who went on tour at short notice to cover special GPS sonde ascents at designated field stations. Our thanks are also due to AMO, ACWC, INSAT-AWS, RS/RW and RMSU, RMC Chennai for their support throughout the programme. iv Contents Chapter Details Page No. 1 Introduction 1 2 Field Operational Centre 2 3 Data sources and Analysis 2 4 Large Scale synoptic features during the IOP, 05-08 Nov 2010 3 5 Description of Weather Summary 4 5.1 Life history of the SCS Jal 4 5.2 Observations and analysis 5 5.2.1 Surface synoptic observations and analysis 5 5.2.2 Upper air observations and Tephigram analysis 6 5.2.3 Satellite products 6 5.2.4 NWP products 7 5.2.5 AWS data 8 6 Conclusions 8 v List of Tables Table No. Details Page No. TABLE 1a List of Surface coastal observatories where hourly special 10 observations were taken TABLE 1b Locations of Sagar Kanya cruise during different instances of IOP 11 period and its distance from the TC centre TABLE 2 Chief rainfall amounts recorded in RMC Chennai region at 03 12 UTC of 05-08 Nov 2010 TABLE 3 Thermodynamic parameters CAPE, CINE and TPWC during 05- 18 08 November 2010 / 00 UTC vi List of figures Fig. No. Details Page No. Fig.1 Locations of stations / Sagar Kanya cruise were special observations were 19 taken Fig.2 IMD’s observed track of SCS ‘Jal’ 20 Fig.3(a-d) Surface Synoptic analysis charts of 05-08 November 2010 / 00 UTC 21-22 Fig.4(a-d) 24 hr pressure departures during05-08 November 2010 / 00 UTC 23 Fig.5(a-d) Surface Humidity during 05-08 November 2010 / 00 UTC 24 Fig.6(a-d) 24 hr accumulated precipitation recorded during 05-08 November 2010 / 03 25 UTC Fig.7(a-d) Plots of surface synoptic observations (3 hourly) at selected stations and in 26-29 Sagar Kanya cruise (6 hourly) during 05-08 November 2010 Fig.8(a-d) Mean upper air winds at 850, 500, 300 & 200 hPa levels during 05-08 30-33 November 2010 Fig.9(a-d) Tephigrams of Karaikal, Chennai(MBK) and Machilipatnam during 00 UTC 34-37 of 05-08 November 2010 (i-iii) Fig.10(a-f) KALPANA-1 OLR (W/m2) for 05-08/00 UTC and 07/06&12 UTC of Nov 38-39 2010 Fig.11 (a-f) KALPANA – 1, Cloud Top Temperature (Below -40˚C) during 05-08/00 40-42 UTC and 07/06&12 UTC Nov 2010 Fig.12(a-d) WRF, HPC, RMC Chennai analysis based on 05-08/00 UTC 43-46 Fig.13(a-d) WRF, HPC, RMC Chennai wind forecasts over Chennai during 05-08 Nov 47-48 2010 Fig.14(a-d) WRF, HPC, RMC Chennai track forecasts of SCS ‘Jal’ 49-50 Fig.15(a&b) WRF, HPC, RMC Chennai Intensity forecasts of SCS ‘Jal’ 51 Fig.16 Plot of AWS observations on 07th/ 16UTC 52 vii viii 1. Introduction The Northeast monsoon season of October to December (OND) is the chief cyclone season over the North Indian Ocean (NIO) even though Tropical Cyclones (TCs) do form during the pre-monsoon months of April-May. On an average, every year, during OND, about 5 depressions form over the NIO out of which, 2 to 3 reach the intensity of Cyclonic Storm (wind speed > 33 knots) & above and 1 to 2 reach the intensity of SCS (wind speed > 64 knots) & above. India, having an extensive coast line, is vulnerable to destructive effects of the landfalling TCs of NIO. Time and again, some of the coastal areas, especially in the eastern coast, have been subjected to the fury of very severe cyclonic storms, in the form of gale force winds, torrential rains and storm surge. There have been extensive loss of life and property due to the devastating effects of the landfalling TCs. Forecasting the formation, movement and coastal crossing of TCs, well in advance of landfall is of utmost importance in order to take necessary disaster mitigatory measures. India Meteorological Department (IMD) is vested with the mandate of forecasting the formation, movement and coastal crossing of TCs that form over the NIO. A lot of research and developmental activities are undertaken by IMD to improve the accuracy and precision of its TC forecasts. One such recent effort, is the Forecast Demonstration Project (FDP) (Cyclone), a Bay of Bengal Tropical Cyclone Experiment planned as an outcome of Indo-US Atmospheric Science Programme. The key scientific objective of the FDP(Cyclone) is to demonstrate the ability of Numerical Weather Prediction (NWP) models to predict the track, intensity and landfall point of Tropical Cyclones over the Bay of Bengal using enhanced observations including measurements from dropsonde over the periphery of the TC and to assess the accuracy limits of the forecasting aspects related to TCs. Various research groups have been encouraged to conduct focused research works in the area of TC forecasting using all the special observational data collected during the experiments. The FDP (Cyclone) is a multi-institutional programme involving all related scientific organisations. The National Operational Centre (NOC) established at the Northern Hemispheric Analysis Centre (NHAC), India Meteorological Department (IMD), New Delhi is responsible for 1 entire coordination of the programme and declaration of Intense Observation Periods (IOPs) during the experiment. A pre-pilot phase of the experiment was conducted during 15 October to 30 November, 2008 (FDP 2008) and a pilot phase of the programme during 15 October to 30 November, 2009 (FDP 2009).