Cloud and precipitation physics - Vancouver 2010 Olympics

The 2010 Vancouver Winter Olympic and Paralympic Games provided a unique opportunity to learn more about cloud and precipitation physics in complex terrain. This was made possible through a WMO World Weather Research Programme project entitled the Science of Nowcasting Winter Weather for Vancouver 2010 (SNOW-V10). A substantial array of research and operations sponsored instrumentation was put in place and some new high resolution models and nowcast systems were tested during the Games. This presentation will focus on the measurements and a few interesting processes that were documented including the following: 1) An array of instruments at several sites up Whistler Mountain, and an instrumented gondola, allowed rain/snow transitions to be observed in detail. 2) Quantitative measurements at four locations along with many video cameras on Whistler Mountain showed reductions in visibility due to precipitation and cloud were highly variable in time and height thus making this important parameter for the sporting events difficult to forecast. 3) A C-Band scanning radar, a vertically pointing radar, and a microwave radiometer, in association with the surface instrumentation, allowed the precipitation formation process from the mountain top to the valley floor to be examined. 4) Cases illustrating the development of an isothermal layer due to snow melting were documented. 5) Several good examples of reduced precipitation in the lee of the Olympic Mountains were observed during this period by both ground based sensors and radars, including the NOAA/OU X-Band Dual- Polarization Radar. 6) Different types of precipitation gauges were co-located at strategic locations allowing a comparison of their ability to measure rainfall and snowfall amounts at high time resolution. An introduction to these process or problems will be given.