Principal ScientistForecast Department, Evaluation Section, Forecast Performance and Productspage tabs Profile Summary: Tim Hewson leads the team responsible for "Forecast Performance Monitoring" and "Product Development" at ECMWF. As such his primary roles are leading the creation of new types of forecast chart, mainly for forecasters, and managing the production of the "Forecast Daily Report". This report is a high-profile internal document that summarises important aspects of the real-time analyses and forecasts of ECMWF's operational models. It aims to bridge the gap between forecast users and model developers in the Research Department, and is pivotal in paving the way for user-related modelling issues to be resolved. Tim also manages the updating of ECMWF's online Forecast User Guide, and its contribution to the Italian-led EU-funded HIGHLANDER project. Within HIGHLANDER ECMWF is creating, for the extended ranges, downscaled 2m temperature and rainfall predictions centred on Italy, and a downscaled probabilistic version of the ERA5 re-analysis, for the same variables, for the whole world. Previously Tim was a Met Office Chief Forecaster, who carried out various related R&D roles alongside. Indeed At ECMWF he also continues to be involved in wide-ranging internal and external research initiatives. Professional interests: Real-time assessment of forecast model performance Invention of new types of forecast chart; optimising the use of colour Mathematical-graphical representation of meteorological features (e.g. fronts, jet streams) Statistical downscaling of model output (rainfall in particular) Understanding and predicting all types of severe weather (notably windstorms in the extra-tropics) Extra-tropical cyclones Predictability at all lead times Training forecast users Collaborative project work - University of Hamburg (3D graphical display, W2W), University of Bergen (air-sea interaction: UNPACC), University of Geneva (precipitation downscaling, ANYWHERE), Technical University of Munich (use of neural networks to downscale wind fields from re-analyses) Career background: Principal Scientist and Team Leader, Forecast Department, ECMWF, 2013-present Senior Scientist (consultant), Operations Department, ECMWF, 2009-2012 Chief Forecaster/Researcher, Met Office, Exeter. 2004-2009 Sabbatical from Met Office, SUNY, Albany, USA. 2004 Research Scientist, Joint Centre for Mesoscale Meteorology (Met Office), Reading University, and Met Office HQ, Bracknell and Exeter, 1990-2003 External recognitions: Atmospheric Science Letters Annual Editor's award 2016 (for outstanding refereeing) Runner up in the Harry Otten Prize for Innovation in Meteorology - 2015 ("A Global Approach to Predicting Flash Floods") Geophysical Research Letters Editor's Award 2011 (for excellence in refereeing) ECMWF representative on the Working Group for Co-operation between European Forecasters (WGCEF, a EUMETNET initiative) ECMWF representative on the Programme and Science Committee for the European Meteorological Society (EMS) Member of the Scientific Advisory Board for Phase 2 of the German transregional "Waves to Weather" (W2W) research programme (2019-2023) Member of the Royal Meteorological Society Publications 2022Stephan Hemri, Timothy Hewson, Estíbaliz Gascón, Jan Rajczak, Jonas Bhend, Christoph Spririg, Lionel Moret, Mark Liniger (August 2022) How do ecPoint precipitation forecasts compare with postprocessed multi-model ensemble predictions over Switzerland? n. 901. DOI: 10.21957/hy89j7svk Fatima Pillosu, Timothy Hewson (June 2022) To what extent does the diagnosis of multiple grid-box weather types add value in post-processing ensemble rainfall forecasts?. DOI: 10.5194/ems2022-671 Estíbaliz Gascón, Augustin Vintzileos, Tim Hewson (June 2022) New probabilistic point forecast products ("ecPoint") for sub-seasonal forecasts and the ERA5 reanalysis - the HIGHLANDER project. DOI: 10.5194/ems2022-457 Andreas Alexander Beckert, Lea Eisenstein, Annika Oertel, Timothy Hewson, George C. Craig, Marc Rautenhaus (July 2022) The three-dimensional structure of fronts in mid-latitude weather systems as represented by numerical weather prediction models. DOI: 10.5194/wcd-2022-36 2021 (May 2021) Major flash floods in Sardinia in November 2020, ECMWF Newsletter. (May 2021) New flash flood forecast products for Italy, ECMWF Newsletter. Timothy Hewson (September 2021) Use and Verification of ECMWF products in Member and Co-operating States, ECMWF Technical Memoranda n. 885. DOI: 10.21957/vp4z0x4yo Timothy David Hewson, Fatima Maria Pillosu (June 2021) A low-cost post-processing technique improves weather forecasts around the world, Communications Earth & Environment. DOI: 10.1038/s43247-021-00185-9 Linus Magnusson, Sharanya Majumdar, Rebecca Emerton, David Richardson, Magdalena A. Balmaseda, Calum Baugh, Peter Bechtold, Jean Bidlot, Antonino Bonanni, Massimo Bonavita, Niels Bormann, Andy Brown, Philip Browne, Hilda Carr, Mohamed Dahoui, Giovanna De Chiara, Michail Diamantakis, David Ian Duncan, Stephen English, Richard Forbes, Alan Geer, Thomas Haiden, Sean Healy, Timothy Hewson, Bruce Ingleby, Martin Janousek, Christian Kühnlein, Simon Lang, Sarah-Jane Lock, Tony McNally, Kristian S. Mogensen, Florian Pappenberger, Inna Polichtchouk, Fernando Prates, Christel Prudhomme, Florence Rabier, Patricia de Rosnay, Tiago Quintino, Michael Rennie (October 2021) Tropical cyclone activities at ECMWF, ECMWF Technical Memoranda n. 888. DOI: 10.21957/zzxzzygwv Estíbaliz Gascón, Augustin Vintzileos, Tim Hewson (June 2021) New ecPoint products for sub-seasonal forecasts and the ERA5 reanalysis - a HIGHLANDER project initiative. DOI: 10.5194/ems2021-85 Estíbaliz Gascón, Andrea Montani, Tim Hewson (June 2021) The MISTRAL Project provides a new tool for Flash Flood Forecasting in Italy . DOI: 10.5194/ems2021-87 2020Timothy Hewson (March 2020) Use and Verification of ECMWF products in Member and Co-operating States (2019), ECMWF Technical Memoranda n. 860. DOI: 10.21957/80s471ib1 Timothy Hewson (March 2020) A Vision for providing Global Weather Forecasts at Point-scale. DOI: 10.5194/egusphere-egu2020-5532 Fu J., Zhang F., Hewson T.D. (2020) Object-Oriented composite analysis of warm-sector rainfall in north China, Monthly Weather Review n. 7, pp. 2719-2735. DOI: 10.1175/MWR-D-19-0038.1 Michael Kern, Kevin Höhlein, Timothy Hewson, Rüdiger Westermann (March 2020) Towards Operational Downscaling of Low Resolution Wind Fields using Neural Networks. DOI: 10.5194/egusphere-egu2020-5447 Kevin Höhlein, Michael Kern, Timothy Hewson, Rüdiger Westermann (November 2020) A comparative study of convolutional neural network models for wind field downscaling, Meteorological Applications n. 6. DOI: 10.1002/met.1961 2019Timothy Hewson (March 2019) Use and Verification of ECMWF Products in Member and Co-operating States (2018), ECMWF Technical Memoranda n. 840. DOI: 10.21957/jgz6nh0uc Kern M., Hewson T., Schätler A., Westermann R., Rautenhaus M. (2019) Interactive 3D Visual Analysis of Atmospheric Fronts, IEEE Transactions on Visualization and Computer Graphics n. 1, pp. 1080-1090. DOI: 10.1109/TVCG.2018.2864806 2018Owens R G, Timothy Hewson (May 2018) ECMWF Forecast User Guide. DOI: 10.21957/m1cs7h Haiden T., Dahoui M., Bruce Ingleby, P. de Rosnay, Crtistina Prates, Ersagun Kuscu, Timothy Hewson, L. Isaksen, David Richardson, Hao Zuo, Luke Jones (November 2018) Use of in situ surface observations at ECMWF, ECMWF Technical Memoranda n. 834. DOI: 10.21957/dj9lpy4wa David Richardson, Timothy Hewson (2018) Use and verification of ECMWF products in Member and Co-operating States (2017), ECMWF Technical Memorandum n. 818. DOI: 10.21957/da8x0wn3i Kern M., Hewson T., Sadlo F., Westermann R., Rautenhaus M. (2018) Robust Detection and Visualization of Jet-Stream Core Lines in Atmospheric Flow, IEEE Transactions on Visualization and Computer Graphics n. 1, pp. 893-902. DOI: 10.1109/TVCG.2017.2743989 Gascón E., Hewson T., Haiden T. (2018) Improving predictions of precipitation type at the surface: Description and verification of two new products from the ECMWF ensemble, Weather and Forecasting n. 1, pp. 89-108. DOI: 10.1175/WAF-D-17-0114.1 Cihan Sahin, Timothy Hewson, Sylvie Lamy-Thepaut, Ivan Tsonevsky, Umberto Modigliani, David Richardson (July 2018) Using ECMWF’s new ensemble vertical profiles, ECMWF Newsletter, issue 156, pp. 37-42. DOI: 10.21957/83cs60nb21 2017 (2017) Meteorological Risk: extra-tropical cyclones, tropical cyclones and convective storms., Science for Disaster Risk Management. (2017) New point-rainfall forecasts for flash flood prediction, ECMWF Newsletter. Timothy Hewson (2017) Use and verification of ECMWF products in Member and Co-operating States (2016), ECMWF Technical Memorandum n. 797. DOI: 10.21957/c8igufhq4 2016Swinbank R., Kyouda M., Buchanan P., Froude L., Hamill T.M., Hewson T.D., Keller J.H., Matsueda M., Methven J., Pappenberger F., Scheuerer M., Titley H.A., Wilson L., Yamaguchi M. (2016) The TIGGE project and its achievements, Bulletin of the American Meteorological Society n. 1, pp. 49-67. DOI: 10.1175/BAMS-D-13-00191.1 2015 (2015) Development of Applications towards a High Impact Weather Forecast System, Seamless Prediction of the Earth System: From Minutes to Months. (2015) Forecasts for a fatal blizzard in Nepal in October 2014, ECMWF Newsletter. (2015) Forecasts for US east coast snow storm in January 2015, ECMWF Newsletter. Hewson T.D., Neu U. (2015) Cyclones, windstorms and the IMILAST project, Tellus, Series A: Dynamic Meteorology and Oceanography n. 1. DOI: 10.3402/tellusa.v67.27128 2014Timothy Hewson, Magnusson L., Ø. Breivik, Fernando Prates, Ivan Tsonevsky, H. J. W. de Vries (2014) Windstorms in northwest Europe in late 2013, ECMWF Newsletter, issue 139, pp. 22-28. DOI: 10.21957/fn6uazeu Richard Forbes, Ivan Tsonevsky, Timothy Hewson, Martin Leutbecher (2014) Towards predicting high-impact freezing rain events, ECMWF Newsletter, issue 141, pp. 15-21. DOI: 10.21957/xcauc5jf Thomas Haiden, Peter Bauer, Jean Bidlot, Laura Ferranti, Timothy Hewson, F. Prates, David Richardson, Frederic Vitart (December 2014) Evaluation of ECMWF forecasts, including 2013-2014 upgrades, ECMWF Technical Memoranda n. 742. DOI: 10.21957/ei4wlemsl Thomas Haiden, Linus Magnusson, Ivan Tsonevsky, Fredrik Wetterhall, L. Alfieri, Florian Pappenberger, Patricia de Rosnay, Joaquin Muñoz-Sabater, Gianpaolo Balsamo, C. Albergel, Richard Forbes, Timothy Hewson, S. Malardel, David Richardson (June 2014) ECMWF forecast performance during the June 2013 flood in Central Europe, ECMWF Technical Memoranda n. 723, pp. 34. DOI: 10.21957/4p9ebc2r3 2013David Richardson, Jean Bidlot, Thomas Haiden, Timothy Hewson, Martin Janousek, F. Prates, Frederic Vitart (November 2013) Evaluation of ECMWF forecasts, including 2012-2013 upgrades., ECMWF Technical Memoranda n. 710, pp. 55. DOI: 10.21957/sle20lpgb Neu U., Akperov M.G., Bellenbaum N., Benestad R., Blender R., Caballero R., Cocozza A., Dacre H.F., Feng Y., Fraedrich K., Grieger J., Gulev S., Hanley J., Hewson T., Inatsu M., Keay K., Kew S.F., Kindem I., Leckebusch G.C., Liberato M.L.R., Lionello P., Mokhov I.I., Pinto J.G., Raible C.C., Reale M., Rudeva I., Schuster M., Simmonds I., Sinclair M., Sprenger M., Tilinina N.D., Trigo I.F., Ulbrich S., Ulbrich U., Wang X.L., Wernli H. (2013) Imilast: A community effort to intercompare extratropical cyclone detection and tracking algorithms, Bulletin of the American Meteorological Society n. 4, pp. 529-547. DOI: 10.1175/BAMS-D-11-00154.1 2012 (2012) Intercomparison of global model precipitation forecast skill in 2010/11 using the SEEPS score, Mon. Wea. Rev., pp. 2720-2733. David Richardson, Jean Bidlot, Laura Ferranti, A Ghelli, Thomas Haiden, Timothy Hewson, Martin Janousek, F. Prates, Frederic Vitart (November 2012) Verification statistics and evaluations of ECMWF forecasts in 2011-2012., ECMWF Technical Memoranda n. 688, pp. 53. DOI: 10.21957/1zh9rr3q6 Haiden T., Rodwell M.J., Richardson D.S., Okagaki A., Robinson T., Hewson T. (2012) Intercomparison of global model precipitation forecast skill in 2010/11 using the SEEPS score, Monthly Weather Review n. 8, pp. 2720-2733. DOI: 10.1175/MWR-D-11-00301.1 Young M.V., Hewson T.D. (2012) The forecasting challenge of waving cold fronts: Benefits of the ensemble approach, Weather n. 11, pp. 296-301. DOI: 10.1002/wea.1977 2011David Richardson, Jean Bidlot, Laura Ferranti, A Ghelli, Thomas Haiden, Timothy Hewson, Martin Janousek, F. Prates, Frederic Vitart (December 2011) Verification statistics and evaluations of ECMWF forecasts in 2010-2011., ECMWF Technical Memoranda n. 654, pp. 50. DOI: 10.21957/35b98nqdn 2010 (2010) Objective identification, typing and tracking of the complete life-cycles of cyclonic features at high spatial resolution, Meteor. Applic., pp. 355-381. DOI: 10.1002/met.204 (2010) White Paper Review on the Verification of Warnings, Met Office. Mark John Rodwell, T. Jung, Peter Bechtold, P. Berrisford, Niels Bormann, Carla Cardinali, Laura Ferranti, Timothy Hewson, Franco Molteni, Nils Wedi, Magdalena A. Balmaseda, Gianpaolo Balsamo, Massimo Bonavita, Roberto Buizza, Mohamed Dahoui, Anotonio Garcia-Mendez, Martin Leutbecher, Philippe Lopez, Y. Trémolet, Frederic Vitart (October 2010) Developments in diagnostics research, ECMWF Technical Memoranda n. 637, pp. 49. DOI: 10.21957/tnuoos42a David Richardson, Jean Bidlot, Laura Ferranti, A Ghelli, Timothy Hewson, Martin Janousek, F. Prates, Frederic Vitart (October 2010) Verification statistics and evaluations of ECMWF forecasts in 2009-2010., ECMWF Technical Memoranda n. 635, pp. 45. DOI: 10.21957/jhsdy3m Rodwell M.J., Richardson D.S., Hewson T.D., Haiden T. (2010) A new equitable score suitable for verifying precipitation in numerical weather prediction, Quarterly Journal of the Royal Meteorological Society n. 650, pp. 1344-1363. DOI: 10.1002/qj.656 2009David Richardson, Jean Bidlot, Laura Ferranti, A Ghelli, C. Gibert, Timothy Hewson, M. Janousek andF. Prates, Frederic Vitart (October 2009) Verification statistics and evaluations of ECMWF forecasts in 2008-2009., ECMWF Technical Memoranda n. 606, pp. 45. DOI: 10.21957/8awjq1gf8 Hewson T.D. (2009) Diminutive frontal waves - A link between fronts and cyclones, Journal of the Atmospheric Sciences n. 1, pp. 116-132. DOI: 10.1175/2008JAS2719.1 (2009) Forecast Product Development at ECMWF, Twelfth Workshop on Meteorological Operational Systems. Timothy Hewson (2009) Tracking fronts and extra-tropical cyclones, ECMWF Newsletter, issue 121, pp. 9-19. DOI: 10.21957/un8liw3vjs 2007Berry G., Thorncroft C., Hewson T. (2007) African easterly waves during 2004 - Analysis using objective techniques, Monthly Weather Review n. 4, pp. 1251-1267. DOI: 10.1175/MWR3343.1 2006 (2006) New Approaches to Verifying Forecasts of Hazardous Weather, 2nd THORPEX International Science Symposium. (2006) The Development of Feature-based Diagnostics to assess TIGGE handling of High-impact extra-tropical Cyclones, 2nd THORPEX International Science Symposium. Berry G.J., Thorncroft C., Hewson T. (2006) Easterly wave diagnostics, 27th Conference on Hurricanes and Tropical Meteorology. 2005 (2005) A UK Met Office perspective on the influences of extra-tropical transition on operational forecasts, 3rd international conference on Extra-Tropical transition. Carroll E.B., Hewson T.D. (2005) NWP grid editing at the Met Office, Weather and Forecasting n. 6, pp. 1021-1033. DOI: 10.1175/WAF872.1 2004 (2004) The value of field modifications in forecasting, Met Office. 2002 (2002) A comparison of Cyclone Spectra in forecasts from the Operational (G1) and New Dynamics trial (NT) versions of the unified model - Aug to Dec 2001, Met Office. Deveson A.C.L., Browning K.A., Hewson T.D. (2002) A classification of FASTEX cyclones using a height-attributable quasi-geostrophic vertical-motion diagnostic, Quarterly Journal of the Royal Meteorological Society n. 579, pp. 93-117. DOI: 10.1256/00359000260498806 2001Hewson T. (2001) The North Sea storm of 30 october 2000, Weather n. 3, pp. 115-116. DOI: 10.1002/j.1477-8696.2001.tb06547.x 2000Hewson T.D., Craig G.C., Claud C. (2000) Evolution and mesoscale structure of a polar low outbreak, Quarterly Journal of the Royal Meteorological Society n. 564, pp. 1031-1063. DOI: 10.1002/qj.49712656411 1999Joly A., Browning K.A., Bessemoulin P., Cammas J.-P., Caniaux G., Chalon J.-P., Clough S.A., Dirks R., Emanuel K.A., Eymard L., Gall R., Hewson T.D., Hildebrand P.H., Jorgensen D., Lalaurette F., Langland R.H., Lemaître Y., Mascart P., Moore J.A., Persson P.O.G., Roux F., Shapiro M.A., Snyder C., Toth Z., Wakimoto R.M. (1999) Overview of the field phase of the Fronts and Atlantic Storm-Track EXperiment (FASTEX) project, Quarterly Journal of the Royal Meteorological Society n. 561, pp. 3131-3163. DOI: 10.1256/smsqj.56101 1998 (1998) A Frontal Wave Database, Met Office. (1998) A JCMM overview of FASTEX IOPs, Met Office. Hewson T.D. (1998) Objective fronts, Meteorological Applications n. 1, pp. 37-65. DOI: 10.1017/S1350482798000553 1997Hewson T.D. (1997) Case work during the Summer Study Week on 'Extra-tropical Cyclones', Meteorological Applications n. 4, pp. 375-378. DOI: 10.1017/S1350482797000728 Hewson T.D. (1997) Objective identification of frontal wave cyclones, Meteorological Applications n. 4, pp. 311-315. DOI: 10.1017/S135048279700073X 1995Browning K.A., Clough S.A., Davitt C.S.A., Roberts N.M., Hewson T.D., Healey P.G.W. (1995) Observations of the mesoscale sub‐structure in the cold air of a developing frontal cyclone, Quarterly Journal of the Royal Meteorological Society n. 526, pp. 1229-1254. DOI: 10.1002/qj.49712152604 1993 (1993) The fronts 92 experiment : A quicklook atlas, Met Office. (1993) Infrared imagery showing cloud evolution in a record(?) Atlantic low - 9/10 January 1993, Meteorological Magazine. (1993) Infrared imagery showing upper level waves - 3 May 1993, Meteorological Magazine. (1993) Thunderstorm activity in a developing cyclone - 4 January 1993, Meteorological Magazine. (1993) Thunderstorms and a gust front - 9 August 1992, Meteorological Magazine n. 1446, pp. 18-20. (1993) Orographic cirrus generated by Iceland and the Faeroe Islands - 4-6 May 1993, Meteorological Magazine. Hewson T.D. (1993) Thunderstorm activity in a developing cyclone - 4 January 1993, Meteorological Magazine n. 1449, pp. 96-98. 1992 (1992) Infrared image of a cloud head - 27 April 1992 at 1800 UTC, Meteorological Magazine. (1992) Hoar-frost deposition on roads, Meteorological Magazine n. 1434, pp. 1-21. 1991 (1991) Temperature predictions for the UK winter, Meteorological Magazine n. 1422, pp. 1-11.