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Verification of forecasts from the 2010 Vancouver Olympic Games. Laurence Wilson Associate Scientist Emeritus Environment Canada Monica Bailey, Marcel Vallee and Ivan Heckmann. Outline. Data Available Observations Forecasts Verification plan Preliminary Results Future.
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Verification of forecasts from the 2010 Vancouver Olympic Games Laurence Wilson Associate Scientist Emeritus Environment Canada Monica Bailey, Marcel Vallee and Ivan Heckmann
Outline • Data Available • Observations • Forecasts • Verification plan • Preliminary Results • Future
Observing sites in the vicinity of Whistler -supplementary obs sites (VOA, VOL etc) -extra in situ instrumentation -radars -profilers
Whistler 15 km 2.5 km 1 km Vancouver Forecasts • GEM-15 km regional model • 2.5 km LAM using bc from regional model • 1 km LAM nested in 2.5 km model • No data assimilation for LAMs • Several nowcast and post-processing systems: • Adaptive blending of observations and models (ABOM), INTW • CMA, ZAMG-INCA, NCAR-WSDDM • Limited UMOS for Olympic sites • Operational forecasts for Olympic venues
Snowboard Men’s Parallel Giant Slalom Final February 27, 2010 Gold Medal to Jassey Jay Anderson of Canada Snowboard spectators stand in the fog during the men's Parallel Giant Slalom snowboarding competition at the Vancouver 2010 Olympics in Vancouver, British Columbia, Saturday, Feb. 27, 2010. (AP Photo/Bela Szandelszky)
Visibility forecasts and obs before mens giant snowboard slalom finals
Snow- V 10 Verification plan • At least two classes of users: • Olympics forecasting team – VANOC • “How accurate are forecasts of weather events significant to VANOC?” • “Should the forecasters have used the nowcast products?” • Modelers • “Are forecasts from the 2.5 km LAM an improvement on the 15km regional forecasts?” • “Are there any advantages to the 1 km grid?” • Two Parts: • user-oriented verification for Olympic period of all forecasts, tuned to decision points of VANOC • Verification of parallel model forecasts for Jan to August 2010 • Rich dataset for user-oriented verification and research: multiple observations at some sites, allows for estimates of observation error
Verification strategy • User-specified thresholds – • categorical/contingency tables • Only surface-defined variables • For user-oriented verification: • Wind, precipitation amount and type, visibility, wind gusts, cloud base height, temperature, humidity • High temporal resolution – 15 minutes 0-2h, hourly after that • During Olympics period only • « representative » point selected in advance by forecasters • For Model verification: • Temperature, precipitation, wind, cloud amount, and possibly ceiling and visibility • From all stations in model domain • 6 months period • At stations, categorical and continuous verification
Preliminary Comparison of Sport Forecast with Canadian Models for Top of Downhill (VOA), Mid-Station (VOL) and Timing Flats (VOT) Wind Direction
Future • Finish verification according to plan based on “standard” data • Special journal issue planned • Comparison with operational forecasts • Verification using “special” data • Higher temporal resolution • Research studies: • Estimating observation error • Model diagnostic studies