Weather forecasts for the 2010 Winter Olympic Games—pre-Games challenges and user requirements in an el Niño season

The XXI Winter Olympic Games were held in Vancouver and Whistler, British Columbia, Canada, February 12-28 2010. Years of planning, forecaster training and development in the areas of NWP and nowcasting resulted in a Games-time meteorological service that met the needs of the Organizing committee, the International Olympic Committee (IOC) and the athletes. A challenge that was not entirely planned for, but met successfully, was the need for detailed weather forecast support in the pre-Games period beginning in November 2009. Climatology had a lot to do with this emergent requirement. A much cooler than normal November and December of 2009 transformed into a significantly warmer January of 2010 under the influence of an increasingly powerful el-Niño and an archetypical blocking and split flow pattern that developed over the west coast of North America during the month. In the early fall of 2009 it became apparent from both NOAA Climate Prediction Center and Environment Canada statistical forecasts that the signal for a positive ENSO phase during the latter half of the winter of 2010 was emerging. Forecast support for snowmaking and field of play snow preservation was prepared for all outdoor venues in the late fall and early winter of 2009, and contingency plans were developed by the organizing committee for extremely mild conditions. The amount of artifical snow produced during the November-December period may well have prevented the complete cancellation of events at least at one venue, Cypress Mountain.