Advancing global NWP through international collaboration

High resolution mean sea level pressure and ensemble spread

Monday 26 October, 00 UTC T+96 Valid: Friday 30 October, 00 UTC

Ensemble forecasts explained
One 'ensemble forecast' consists of 51 separate forecasts made by the same computer model, all activated from the same starting time. The starting conditions for each member of the ensemble are slightly different, and physical parameter values used also differ slightly. The differences between these ensemble members tend to grow as the forecasts progress, that is as the forecast lead time increases..

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ECMWF Summer of Weather Code – a driver of innovation

Julia Wagemann and Esperanza Cuartero discuss the exciting developments from this summer's ESoWC, which gives developers the opportunity to work with ECMWF mentors to solve a range of challenges facing the Centre.

26 October 2020

Schematic of the reanalysis process

Fact sheet: Reanalysis

Reanalysis data provide the most complete picture currently possible of past weather and climate. This fact sheet explains what reanalysis is and what it is used for.


Forecast charts and data

We provide current forecasts, climate reanalyses and specific datasets. These are available via the web, point-to-point dissemination, data servers and broadcasting.

IFS 47r1 upgrade image for documentation

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Full documentation is now available for Cycle 47r1 of ECMWF’s Integrated Forecasting System (IFS), which became operational in July this year. IFS documentation #IFS47r1


Forecasts, analyses, climate re-analyses, reforecasts and multi-model data are available from our archive (MARS) or via dedicated data servers or via point-to-point dissemination.

Accessing forecasts

Researchers, WMO members, commercial users and satellite data providers can gain access to ECMWF forecast products under one of our various license agreement types.

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Serving meteorology

International collaboration is fundamental to the work of ECMWF, working with the EU and the meteorological community at large, including the World Meteorological Organization, space agencies, and scientists around the world.