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Solid precipitation intensity, snow density, wind speed, and temperature were collected from November 2009 to February 2010 at a naturally sheltered station located at an altitude of 1640 m MSL on Whistler Mountain in British Colombia, Canada. The snowfall was measured using the instruments OTT Pluvio; the Yankee Environmental Systems, Inc., hot plate (HP); and the Vaisala FD12P (optical weather sensor). The snow amount and density were also measured manually daily. The observed wind speeds were in the range 0-4.5 m s 21 with a mean value of 0.5 m s 21 . Based on this study, the HP overestimated the snow amount by about a factor of 2 as compared to the Pluvio measurements. Further data analysis using the raw output HP data suggests that this was because of false precipitations produced, particularly by the downslope flows in the complex terrain when the wind speeds were relatively stronger. This false precipitation varied from 20.9 to 1.3 mm h 21 with two peaks at 0.1 and 0.3 mm h 21 depending on wind speed-the larger peak being at higher wind speeds. Since the observed wind speeds were relatively calm, setting the correction factor to 0.15 mm h 21 gave reasonable values as compared to the Pluvio data. The difference between the corrected HP and Pluvio accumulation data varied from 16% to 3% depending on wind speed. The observed snow density in January 2010 varied from 0.04 to 0.32 g cm 23 with a mean value of 0.08 g cm 23 . The snow amount measured using the corrected HP data agreed well with the manually measured values with a correlation coefficient of 0.93.

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he Olympics inspire greatness. "Swifter, Higher, Stronger" applies not only to the athletes but sets the tone for everyone associated with the games, including the weather service providers. The Winter Olympic and Paralympic Games of 2010 will be hosted by the city of Vancouver, British Columbia, from 12-28 February and 12-21 March, respectively. Alpine and Nordic events will be held on Whistler Mountain, at the new Whistler Olympic Park in the Callaghan Valley and at Cypress Mountain on the North Shore Mountains just north of the City of Vancouver (Fig.1). The challenges for winter weather forecasting and nowcasting in complex terrain within a coastal region require Olympian efforts and innovations to overcome. The International Olympic Committee (IOC) awarded the games to Vancouver on 2 July 2003. Environment Canada (EC), with its federal mandate to Weather Services, Science Advances, and the Vancouver 2010 Olympic and Paralympic Winter Games