Timothy Hewson

Principal Scientist
Forecast, Evaluation, Forecast Performance and Products


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