ECMWF Ensemble

The ensemble of the European Centre for Medium-Range Weather Forecasts (ECMWF), an intergovernmental organisation of European states. ECMWF runs its global model 51 times from slightly different starting conditions, to show how certain the forecast is. From these 51 runs we count, at every place and time, the share that goes above a threshold: wind, gusts, waves, and waves and wind together in the same run.

The app shows these shares as probabilities, not as a forecast to route on. The colour on the map is the share of runs, not a wind speed or a wave height. See Planning a passage for how to use it.