Minimizing the terrain blockage is fundamental for the selection of weather radar sites. We present here a numerical model for simulating surveillance coverage of weather radars under complex terrain conditions. As input, our simulation uses a terrain digital model, the weather radar parameters, and radiosonde observations of the vertical profile of temperature, pressure and vapor mixing ratio. We validate our coverage model using observations from Environment Canada's weather radar located at Mount Sicker (British Columbia). As an application, we present the expected coverage for a new weather radar to be installed at Whistler (British Columbia). This new radar is been built by Environment Canada to support the forecasting operations during the 2010 Winter Olympic and Paralympic Games, in Vancouver (British Columbia).