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Data and Products of the Global Ensemble Prediction System (GEPS)

The Global Ensemble Prediction System (GEPS) carries out physics calculations to arrive at probabilistic predictions of atmospheric elements from the current day out to 16 days into the future (up to 32 days once a week on Thursdays at 00UTC). The GEPS produces different outlooks (scenarios) to estimate the forecast uncertainties due the nonlinear (chaotic) behaviour of the atmosphere. The probabilistic predictions are based on an ensemble of 20 scenarios that differ in their initial conditions, choice of physics parametrization as well as stochastic perturbations (physical tendencies and kinetic energy). A control member that is not perturbed is also available. Weather elements include temperature, precipitation, cloud cover, wind speed and direction, humidity and others. This product contains raw numerical results of these calculations. Geographical coverage is global. The horizontal resolution of the system is 0.35 degree (about 39 km at equator). The system has 45 vertical levels for the forecasts and 81 vertical levels for the analyses. Predictions are performed twice a day.


How to access the data

This data is available on the MSC GeoMet API / web services and the MSC Datamart data server:

An overview and examples to access and use the Meteorological Service of Canada's open data is available. Example of a web map configured to display the GEPS.DIAG.12_PRMM.ERGE10 layer served by MSC GeoMet:


The end-user licence for Environment and Climate Change Canada's data servers specifies the conditions of use of this data.



Technical documentation


The chronology of changes to the Global Ensemble Prediction System (GEPS) is available in the changelog.