Research and development work at Meteorological Research Division (MRD) in collaboration with Canadian Meteorological Centre (CMC) will result in better weather forecasts across Canada. A goal of the MRD is to provide the CMC with state of the art numerical systems (models) for weather prediction, such as the Regional Forecasting System. This system, dedicated to weather forecasts across Canada up to a lead time of 48 hours, had major upgrades become operational in October.

The two main components of the Regional Forecasting System are the data assimilation system and a limited area model covering North America and large portions of the three adjacent oceans. The data assimilation system provides the initial conditions from which the Regional Model is launched every 6 hours for 48 hour forecasts. 

Upgrades to the system include the 3D-Var (3-Dimensional Variational) data assimilation system being upgraded to a 4D-Var. Overall, at least two times more observations are assimilated in the new system, improving the robustness and quality of the initial conditions. The horizontal grid spacing of the RDPS is decreased from 15 to 10 km, allowing a more realistic simulation of small-scale phenomena and topographical effects such as valley winds and sea breezes. Furthermore, the sub-grid scale parameterizations of the model have been improved. This provides more realistic forecasts of precipitation type and surface air temperature in winter and spring warm frontal situations. The improved initial conditions provided by 4D-Var, the reduced grid spacing and improved parameterizations will result in better weather forecasts.

Contact: Paul Vaillancourt, (514) 421-4783, Paul.Vaillancourt@ec.gc.ca, Atmospheric Numerical Prediction Research; and Luc Fillion, (514) 421-4770, Luc.Fillion@ec.gc.ca, Data Assimilation and Satellite Meteorology / Meteorological Research Division, Atmospheric Science and Technology Directorate