The European Forecaster Newsletter of the WGCEF N° 23 September 2018 C ontents 3 Introduction Minutes of the 23rd Annual Meeting of the Working Group on Co-operation 4 Between European Forecasters (WGCEF) Sting Jets and other processes leading to high wind gusts: 10 wind-storms “Zeus” and “Joachim” compared 16 Forecasting Freezing Rain in the UK – March 1st and 2nd 2018 24 The Extreme Wildfire, 17-19 July 2017 in Split 30 Changing the Way we Warn for Weather Storm naming: the First Season of Naming by the South-west Group: 33 Spain-Portugal-France 38 Can we forecast the sudden dust storms impacting Israel's southernmost city? 45 The 31st Nordic Meteorological Meeting 46 Representatives of the WGCEF Cover: Ana was the first storm named by the Southwest Group (Spain, Portugal, France) during winter 2017-2018. It affected three countries with great impacts. Printed by Meteo France Editors Stephanie Jameson and Will Lang, Met Office Layout Kirsi Hindstrom- Basic Weather Services Published by Météo-France Crédit Météo-France COM/CGN/PPN - Trappes I ntroduction Dear Readers and Colleagues, It’s a great pleasure to introduce the 23rd edition of our newsletter ‘The European Forecaster’. The publica- tion is only possible due to the great work and generosity of Meteo-France, thus we want to express our warmest gratitude to Mr. Bernard Roulet and his colleagues. We kindly thank all the authors for submitting articles, particularly as they all work in operational forecasting roles and thus have only limited time for writing an article. Many thanks go to Mrs. Stephanie Jameson, Dr. Will Lang, Mrs. Evelyn Cusack and Ms. Laura Paterson for reviewing the incoming articles. Last, but not least, we want to thank Dr. Andre-Charles Letestu for updating our WGCEF website www.euroforecaster.org regularly. During recent months, the weather has been quite exciting. A strong zonal flow during late autumn and early winter brought many storms to western and north-western Europe (e.g. storms Caroline, Dylan and Carmen) and to south-western Europe (storms Ana and Bruno) as well. Some storms also affected central Europe, like storms Eleanor or David. Most of these weather events were associated with strong wind gusts, but some were associated with high precipitation amounts too - especially in the higher parts of the Alps, where new snow records were observed. By the end of January, the weather regime changed; during February and March cold continental air from the north-east influenced many parts of Europe. Whereas in central and eastern parts of Europe these air masses were often dry, over the United Kingdom and Ireland, blizzard-like snowfall conditions were observed (referred to as the ‘Beast from the East’ by the media). During April the winter conditions turned rapidly into summer ones. Very warm air masses from the south, and later on from the east, covered central and eastern Europe and even some parts of Scandinavia and the UK. This air was unstable, especially over central Europe, and therefore many thunderstorms occurred. As a result of the weak flow, these thunderstorms moved very slowly or even stayed over the same region for many hours, therefore accumulating more than 100mm of rain within a short period. This led to many flash floods and landslides in those areas. As forecasters we are taking a leading role in supporting people, decision-makers and civil protection agen- cies in being prepared for these severe weather events - to minimise, or even avoid, damage to humans and infrastructure. To keep, or even improve, the high quality of our forecasts, cooperation and scientific exchange between the different NMSs is essential, which is one important goal of our working group. Finally, we want to send many thanks to Mrs. Julianna Drozdzynska, Mr. Piotr Manczak and their colleagues who organised and hosted our excellent 2017 meeting in Warsaw. We hope you find this newsletter enjoyable and informative. Best regards, Christian Csekits and Jos Diepeveen Chairpersons WGCEF The European Forecaster 3 Minutes of the 23rd Annual Meeting of the Working Group on Co-operation Between European Forecasters (WGCEF) Thursday 12th – Friday 13th October 2017 Warsaw, Poland OGRODNIK, Michal - IMGW/Hydrometeorolo- gical Service of Poland PATKAI, Zsolt - OMSZ/Hungary RALIENE, Vida - Hydrometeorological Service of Lithuania REY, Jaime - AEMET/Spain ROULET, Bernard - Meteo France SANDEV, Marjan - Czech Hydrometeorological Institute SKELBAEK, Michael - DMI/Denmark List of Participants (in alphabetical order): VANHAMEL, Thomas - RMI/Belgium Participants via videoconference: BLAAUBOER, Dick - Eumetnet Mr. Attilio DI DIODATO (Italy), Mr. Panos GIANNOPOU- CSEKITS, Christian - ZAMG/Austria LOS (Greece); Mr. Andre-Charles LETESTU (Switzerland); Mr Mats Johansson, SHMI (Sweden). CUSACK, Evelyn - MET EIREANN/Ireland DIEPEVEEN, Jos - KNMI/The Netherlands Meeting Venue: Institute of Meteorology and Water Management – DOUBLET, Karen Helen - Met Norway National Research Institute DROZDZYNSKA, Julianna - MGW/ ul. Podleśna 61 Hydrometeorological Service of Poland 01-673 Warszawa HAUSEN, Robert - DWD/Germany Thursday, 12th of October HEWSON, Tim - ECMWF HLADNIK, Veronika - Slovenian Environmental Introduction Agency IMGW Deputy Director General Piotr Kowalczak JAMESON, Stephanie - UK Met Office welcomed the WG to Warsaw and introduced the JONASDOTTIR, Elín Björk - Icelandic Met Office participants to the IMGW facilities. KALIN, Lovro - DHMZ/Meteorological and As WG Chair, Christian thanked Piotr and made his Hydrometeorological Service of Croatia introductory remarks. Christian and Jos then KRUMINA, Laura - Latvian Environment, welcomed the new members to the group: Jaime Rey from Spain, Laura Krumina from Latvia, Elin Geology and Meteorology Centre (LEGMC) Bjork Jonasdottir from Iceland and Stephanie LAINE, Mikko - FMI/Finland Jameson from the UK. LEITAO, Paula - PMA/Portugal In an overview of group activities, Christian noted MANCZAK, Piotr - MGW/Hydrometeorological that WGCEF delegates were Co-Chairs in the Service of Poland Forecasters’ Session of the EMS Annual Conference, 4 The European Forecaster which took place in Dublin from 4 th to 8 th of • At the beginning of October, KNMI launched new app. September 2017 (Evelyn Cusack and Christian • Development of own visualisation and production Csekits). Furthermore the WGCEF Chair is member of system, Geoweb. the PSC, the programme and science committee of the EMS. Karen Helen Doublet /Norwegian Met Service WGCEF was also heavily involved in the Eumetnet • Several episodes of extreme precipitation Task Team on Improved Services and Impact Based events/flooding during the last year, and there is a Warnings (Laura Paterson, Jos Diepeveen and project to update extreme weather warning plans. Christian Csekits). WGCEF has also participated in • NWP cooperation between SMHI and METNorway will the Eumetnet Drafting Team on forecasting (Jos include FMI this year. Ensemble system MEPS 2.5 km, Diepeveen and Christian Csekits). 10 members. Cooperation on a HPC-solution as well • New trajectory models for drifting objects. Flexible The meeting agenda was agreed and actions from solution, different modules: drifting oil slick, persons the last meeting were agreed. in water, different objects. General input data: current, waves and wind Members’ Updates • Developing finemesh models in coastal areas and in fjords: In this round table session, participants were invit- - grid size 800 m, wave model and ocean ed to introduce themselves and give a short update model. on new developments within their NMS. - grid size 2.5 km atmospheric model. Cristian Csekits, ZAMG/Austria Robert Hausen DWD/Germany • During nights there is now only one technical shift • Change in DWD-law regarding providing free data (instead of two; operational since summer 2017) • The “Sinfony“project is developing an integrated • New ZAMG-App for fire brigade, police and ambu- forecast system lance • Add-on DWD-App: warnings and reports for flood- • INCA now uses forecast data from AROME (instead ings, storm tides and avalanches of ALARO) from 2018/19 on • New operational forecasting and emergency room (7 Tim Hewson, ECMWF instead of 4 positions) ready in November 2017 • Agreement reached that ECMWF computing facilities – notably the next -Supercomputer – will be re-located Evelyn Cusack, Met Eireann to Bologna in Italy • New Assistant Director: Dr Sarah O'Reilly • Two new model cycles were introduced since the 8 new meteorologists are training at KNMI: last WGCEF meeting. New seasonal forecast system October/November/December. KNMI trainers coming (System 5) will become operational in November. to Dublin in January and February. • For the recent devastating hurricanes in the North • European Met Society in Dublin was a great Atlantic ECMWF forecasts, though not perfect, outper- success.....the largest ever over 850 (110 from formed forecasts from other centres (including special Ireland). Met Eireann had a follow-on 1-day seminar in high resolution LAMs). October 2018 which energized all the staff. We gave 15-minute presentations from EMS. Veronika Hladnik, Slovenian • We continue to automate remote rainfall stations in Environmental Agency mountains etc and 60 are being tested. • Implementation of Aladin-SI model version CY40 • Facebook account Arso Vreme Jos Diepeveen KNMI/Netherlands • Rejuvenation of the forecasting team Facebook • There is ambition to develop to an Early Warning account Arso Vreme. Centre Devastating hurricane Irma hits the SSS Islands in the Stephanie