The Global Environmental Multiscale Model (GEM), often known as the CMC model in North America, is an integrated forecasting and data assimilation system developed in the Recherche en Prévision Numérique (RPN), Meteorological Research Branch (MRB), and the Canadian Meteorological Centre (CMC).
A regional ensemble prediction system (REPS), covering North America and also having 20 members plus control, runs out 72 hours.
The GEM model has been developed to meet the operational weather forecasting needs of Canada for the coming years.
The operational GEM model dynamics is formulated in terms of the hydrostatic primitive equations with a terrain following pressure vertical coordinate (h).
The strategy is progressing towards a unified data assimilation and forecast system, at the heart of which lies a single multipurpose and multiscale numerical model.