Jonathan Day

Forecast Department, Evaluation Section, Diagnostics


Jonny is a scientist at European Centre for Medium-Range Weather Forecasts (ECMWF) working on weather and climate processes and prediction. He is a member of the Diagnostics Team at ECMWF, focusing on developing understand the causes of forecast error from a process perspective.

He is recognised internationally as an expert on polar meteorology and sea ice prediction.

Professional interests:
  • Coupled weather and climate processes

  • Predictability and prediction

  • Process-oriented forecast evaluation

  • Sea ice prediction

  • Climate change in high latitudes

  • Arctic storms and extreme events

Career background:

Before joining ECMWF in 2017 Jonny was an AXA Post-Doctoral Research Fellow at the University of Reading. His research focussed on Arctic cyclones, sea ice prediction and polar climate processes. Before this he was a Post-Doc at the Japan Agency for Marine Earth Science and Technology (JAMSTEC). He received his PhD from the University of Bristol in 2011.

External recognitions

Jonny is a steering group member of the World Weather Research Program – Polar Prediction Project, a 10 year WMO initiative designed to improve the provision of polar weather forecasting in the polar regions.