Interpretation and comparison of Doppler observations in complex terrain with a high resolution numerical weather prediction models during the Vancouver 2010 Olympic Winter Games

A Doppler radar was installed in the Whistler Valley for the Vancouver 2010 Winter Olympic and Paralympic Games. This unique radar was located at the confluence of three valleys and was severely blocked at low levels. Thirteen degree elevation angle plan position indicator scans cleared the nearby mountains. Unlike most operational radars, this radar was sited and configured for local applications (less than 30 km range), winter conditions (less than 10-12 km echo tops) and for complex terrain (RHI scans over key sites and down critical valleys). With local winds generated by inflow-outflow at low levels, drainage flows and diurnal thermally driven upslope flows, precipitation driven diabatic down and upslope winds and system driven flows aloft, the radial velocity observations were quite complex and difficult to manually interpret. For the Olympic Games, Environment Canada employed high resolution models (2.5 and 1.0 km grid resolution) over the area of interest that proved to be very useful for forecasting various weather elements. Post-Olympics, radial velocity images were created from the model wind fields for validation purposes and to compare with the observations. These model generated radial velocity images showed that the model was adept at replicating the details of the wind fields. Preliminary analysis indicated the the magnitude of the winds may be lower than reality, nonetheless they greatly aided in the interpretation of wind fields and particularly in understanding in the meteorology in complex terrain.