Meteorological observations of rain/snow transition made on Whistler Mountain during SNOW-V10

The transition between types of precipitation is an area of research that requires in-situ measurements to improve model representation and forecast skill. During the winter, Whistler Village is prone to rain due to the transition from snow along nearby slopes. The Whistler area is therefore an ideal location to study the transition region. Detailed measurements conducted along Whistler Mountain in conjunction with SNOW-V10 consisted of snowflake micro-photography at Roundhouse station, observations of the precipitation types associated with the rain-snow transition along the mountainside, and profiles of temperature and humidity from Roundhouse Station down to Whistler Village (~1,150 m). Notable findings include the sharpness of the transition region (less than 100 m), the typical variation of strong winds above and calm winds below the transition, and the wide variety of crystal types and the degree of riming in the snow region. This paper will overview the photographic and profiling techniques used and will provide an initial analysis of a selection of events will be presented, utilizing SNOW-V10 Doppler Radar, profiling MWR, MRR, and surface observations.