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.
- 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)
- 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
- 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
- 2024
- Fatima Pillosu, Tim Hewson, Chiara Cagnazzo (August 2024) ERA5-ecPoint: what it is and its power in the contextualisation of severe temperatures and rainfall. DOI: 10.5194/ems2024-1065
- (September 2024) Use and Verification of ECMWF products, Technical Memoranda n. 919. DOI: 10.21957/734d5d4d39
- Estíbaliz Gascón, Andrea Montani, Tim D. Hewson (July 2024) Post‐processing output from ensembles with and without parametrised convection, to create accurate, blended, high‐fidelity rainfall forecasts, Quarterly Journal of the Royal Meteorological Society. DOI: 10.1002/qj.4753
- Nigel Roberts, Timothy Hewson (August 2024) Combining ensembles using a new synoptic-scale curvature diagnostic. DOI: 10.5194/ems2024-349
- 2023
- Kevin Höhlein, Tim Hewson (July 2023) 2m Temperature Downscaling with Dynamic Lapse Rates. DOI: 10.5194/ems2023-301
- Tim Hewson (July 2023) A Record Breaking Extratropical Cyclone in 2022: A Sign of Climate Change ?. DOI: 10.5194/ems2023-303
- Fatima Pillosu, Tim Hewson, Christel Prudhomme, Hannah Cloke (July 2023) How are observed point-rainfall climatologies represented by global models with different spatial resolutions? A comparative study.. DOI: 10.5194/ems2023-610
- Andreas A. Beckert, Lea Eisenstein, Annika Oertel, Tim Hewson, George C. Craig, Marc Rautenhaus (January 2023) The three-dimensional structure of fronts in mid-latitude weather systems as represented by numerical weather prediction models. DOI: 10.5194/gmd-2022-278
- Andreas A. Beckert, Lea Eisenstein, Annika Oertel, Tim Hewson, George C. Craig, Marc Rautenhaus (August 2023) The three-dimensional structure of fronts in mid-latitude weather systems in numerical weather prediction models, Geoscientific Model Development. DOI: 10.5194/gmd-16-4427-2023
- 2022
- (August 2022) How do ecPoint precipitation forecasts compare with postprocessed multi-model ensemble predictions over Switzerland?, ECMWF Technical Memoranda 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 I. 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
- 2020
- Fu J., Zhang F., Hewson T.D. (December 2020) Object-Oriented composite analysis of warm-sector rainfall in north China, Monthly Weather Review. DOI: 10.1175/MWR-D-19-0038.1
- Timothy 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
- 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
- Timothy Hewson (March 2020) A Vision for providing Global Weather Forecasts at Point-scale. DOI: 10.5194/egusphere-egu2020-5532
- 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
- 2019
- Kern M., Hewson T., Schätler A., Westermann R., Rautenhaus M. (December 2019) Interactive 3D Visual Analysis of Atmospheric Fronts, IEEE Transactions on Visualization and Computer Graphics. DOI: 10.1109/TVCG.2018.2864806
- Timothy 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
- 2018
- David Richardson, Timothy Hewson (December 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. (December 2018) Robust Detection and Visualization of Jet-Stream Core Lines in Atmospheric Flow, IEEE Transactions on Visualization and Computer Graphics. DOI: 10.1109/TVCG.2017.2743989
- Gascón E., Hewson T., Haiden T. (December 2018) Improving predictions of precipitation type at the surface: Description and verification of two new products from the ECMWF ensemble, Weather and Forecasting. DOI: 10.1175/WAF-D-17-0114.1
- Owens 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
- 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
- (December 2017) Meteorological Risk: extra-tropical cyclones, tropical cyclones and convective storms., Science for Disaster Risk Management.
- (December 2017) New point-rainfall forecasts for flash flood prediction, ECMWF Newsletter.
- Timothy Hewson (December 2017) Use and verification of ECMWF products in Member and Co-operating States (2016), ECMWF Technical Memorandum n. 797. DOI: 10.21957/c8igufhq4
- 2016
- Swinbank 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. (December 2016) The TIGGE project and its achievements, Bulletin of the American Meteorological Society. DOI: 10.1175/BAMS-D-13-00191.1
- 2015
- (December 2015) Development of Applications towards a High Impact Weather Forecast System, Seamless Prediction of the Earth System: From Minutes to Months.
- (December 2015) Forecasts for a fatal blizzard in Nepal in October 2014, ECMWF Newsletter.
- (December 2015) Forecasts for US east coast snow storm in January 2015, ECMWF Newsletter.
- Hewson T.D., Neu U. (December 2015) Cyclones, windstorms and the IMILAST project, Tellus, Series A: Dynamic Meteorology and Oceanography. DOI: 10.3402/tellusa.v67.27128
- 2014
- Richard Forbes, Ivan Tsonevsky, Timothy Hewson, Martin Leutbecher (December 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
- Timothy Hewson, Magnusson L., Ø. Breivik, Fernando Prates, Ivan Tsonevsky, H. J. W. de Vries (December 2014) Windstorms in northwest Europe in late 2013, ECMWF Newsletter, issue 139, pp. 22-28. DOI: 10.21957/fn6uazeu
- 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
- 2013
- 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. (December 2013) Imilast: A community effort to intercompare extratropical cyclone detection and tracking algorithms, Bulletin of the American Meteorological Society. DOI: 10.1175/BAMS-D-11-00154.1
- David 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
- 2012
- (December 2012) Intercomparison of global model precipitation forecast skill in 2010/11 using the SEEPS score, Mon. Wea. Rev..
- 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. (December 2012) Intercomparison of global model precipitation forecast skill in 2010/11 using the SEEPS score, Monthly Weather Review. DOI: 10.1175/MWR-D-11-00301.1
- Young M.V., Hewson T.D. (December 2012) The forecasting challenge of waving cold fronts: Benefits of the ensemble approach, Weather. DOI: 10.1002/wea.1977
- 2011
- David 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
- (December 2010) Objective identification, typing and tracking of the complete life-cycles of cyclonic features at high spatial resolution, Meteor. Applic.. DOI: 10.1002/met.204
- (December 2010) White Paper Review on the Verification of Warnings, Met Office.
- Rodwell M.J., Richardson D.S., Hewson T.D., Haiden T. (December 2010) A new equitable score suitable for verifying precipitation in numerical weather prediction, Quarterly Journal of the Royal Meteorological Society. DOI: 10.1002/qj.656
- 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
- 2009
- (December 2009) Forecast Product Development at ECMWF, Twelfth Workshop on Meteorological Operational Systems.
- Hewson T.D. (December 2009) Diminutive frontal waves - A link between fronts and cyclones, Journal of the Atmospheric Sciences. DOI: 10.1175/2008JAS2719.1
- Timothy Hewson (December 2009) Tracking fronts and extra-tropical cyclones, ECMWF Newsletter, issue 121, pp. 9-19. DOI: 10.21957/un8liw3vjs
- David 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
- 2007
- Berry G., Thorncroft C., Hewson T. (December 2007) African easterly waves during 2004 - Analysis using objective techniques, Monthly Weather Review. DOI: 10.1175/MWR3343.1
- 2006
- (December 2006) New Approaches to Verifying Forecasts of Hazardous Weather, 2nd THORPEX International Science Symposium.
- (December 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. (December 2006) Easterly wave diagnostics, 27th Conference on Hurricanes and Tropical Meteorology.
- 2005
- (December 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. (December 2005) NWP grid editing at the Met Office, Weather and Forecasting. DOI: 10.1175/WAF872.1
- 2004
- (December 2004) The value of field modifications in forecasting, Met Office.
- 2002
- (December 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. (December 2002) A classification of FASTEX cyclones using a height-attributable quasi-geostrophic vertical-motion diagnostic, Quarterly Journal of the Royal Meteorological Society. DOI: 10.1256/00359000260498806
- 2001
- Hewson T. (December 2001) The North Sea storm of 30 october 2000, Weather. DOI: 10.1002/j.1477-8696.2001.tb06547.x
- 2000
- Hewson T.D., Craig G.C., Claud C. (December 2000) Evolution and mesoscale structure of a polar low outbreak, Quarterly Journal of the Royal Meteorological Society. DOI: 10.1002/qj.49712656411
- 1999
- Joly 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. (December 1999) Overview of the field phase of the Fronts and Atlantic Storm-Track EXperiment (FASTEX) project, Quarterly Journal of the Royal Meteorological Society. DOI: 10.1256/smsqj.56101
- 1998
- (December 1998) A Frontal Wave Database, Met Office.
- (December 1998) A JCMM overview of FASTEX IOPs, Met Office.
- Hewson T.D. (December 1998) Objective fronts, Meteorological Applications. DOI: 10.1017/S1350482798000553
- 1997
- Hewson T.D. (December 1997) Case work during the Summer Study Week on 'Extra-tropical Cyclones', Meteorological Applications. DOI: 10.1017/S1350482797000728
- Hewson T.D. (December 1997) Objective identification of frontal wave cyclones, Meteorological Applications. DOI: 10.1017/S135048279700073X
- 1995
- Browning K.A., Clough S.A., Davitt C.S.A., Roberts N.M., Hewson T.D., Healey P.G.W. (December 1995) Observations of the mesoscale sub‐structure in the cold air of a developing frontal cyclone, Quarterly Journal of the Royal Meteorological Society. DOI: 10.1002/qj.49712152604
- 1993
- (December 1993) The fronts 92 experiment : A quicklook atlas, Met Office.
- (December 1993) Infrared imagery showing cloud evolution in a record(?) Atlantic low - 9/10 January 1993, Meteorological Magazine.
- (December 1993) Infrared imagery showing upper level waves - 3 May 1993, Meteorological Magazine.
- (December 1993) Thunderstorm activity in a developing cyclone - 4 January 1993, Meteorological Magazine.
- (December 1993) Thunderstorms and a gust front - 9 August 1992, Meteorological Magazine.
- (December 1993) Orographic cirrus generated by Iceland and the Faeroe Islands - 4-6 May 1993, Meteorological Magazine.
- Hewson T.D. (December 1993) Thunderstorm activity in a developing cyclone - 4 January 1993, Meteorological Magazine.
- 1992
- (December 1992) Infrared image of a cloud head - 27 April 1992 at 1800 UTC, Meteorological Magazine.
- (December 1992) Hoar-frost deposition on roads, Meteorological Magazine.
- 1991
- (December 1991) Temperature predictions for the UK winter, Meteorological Magazine.