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TOC > MSC data > GEPS

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 39 days twice a week on Mondays and Thursdays at 00UTC for calculating forecast anomalies). The GEPS produces different outlooks (scenarios) to estimate the forecast uncertainties due to the nonlinear (chaotic) behaviour of the atmosphere. The probabilistic predictions are based on an ensemble of 20 scenarios that differ in their initial conditions, their physics parameters which are randomly perturbed by a Stochastic Parameter Perturbation (SPP) method, and the stochastic perturbations (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 0.23 degree (about 25 km at equator). The system has 84 vertical levels for the forecasts and 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.

MSC Open Data Service Usage Policy

The MSC Open Data Service Usage Policy determines what constitutes an acceptable use of MSC Open Data services and provides users best practices for optimal use.



Technical documentation


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