Advancing global NWP through international collaboration

High resolution mean sea level pressure and ensemble spread

Friday 23 March, 12 UTC T+96 Valid: Tuesday 27 March, 12 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 uses data from extra radiosondes launched in the Arctic

Weather data collected by radiosondes launched in the Arctic in February and March 2018 as part of the Year of Polar Prediction are feeding into ECMWF forecasts. The availability of such observations is significant as this region is normally only sparsely observed.

16 March 2018

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.

Global total column water vapour

Plot of the week

Global total column water vapour for 36 hours in the ECMWF forecast from 00 UTC 20 March 2018. Tropical cyclones are seen over the Indian Ocean, and the atmospheric river affecting California is visible.


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.

Advancing weather science

Education is a key element of our work at ECMWF, enabling our partners to get the most from ECMWF's services and develop an advanced understanding of forecasting.

ECMWF lecture theatre

ECMWF workshops are open to the worldwide meteorological community, though some training is restricted to member states.