Adaptive Blending of Model and Observations for Automated Short-Range Forecasting: Examples from the Vancouver 2010 Olympic and Paralympic Winter Games

• Published in: Pure and applied geophysics Vol. 171; no. 1-2; pp. 257 - 276
• Main Authors: Bailey, Monika E., Isaac, George A., Gultepe, Ismail, Heckman, Ivan, Reid, Janti
• Format: Journal Article
• Language: English
• Published: Basel Springer Basel 01.01.2014; Springer Nature B.V
• Subjects: Blending; Climatology; Earth and Environmental Science; Earth Sciences; Extrapolation; Games; Geophysics/Geodesy; Mathematical analysis; Mathematical models; Meteorology; Olympic games; Paralympic Games; Relative humidity; Stations; Weather forecasting; Wind speed; Winter; Vancouver British Columbia Canada; Canada; Heidke Skill Score; Lead Time; Mean Absolute Error; Forecast Lead Time; Numerical Weather Prediction
• ISSN: 0033-4553; 1420-9136
• DOI: 10.1007/s00024-012-0553-x

An automated short-range forecasting system, adaptive blending of observations and model (ABOM), was tested in real time during the 2010 Vancouver Olympic and Paralympic Winter Games in British Columbia. Data at 1-min time resolution were available from a newly established, dense network of surface observation stations. Climatological data were not available at these new stations. This, combined with output from new high-resolution numerical models, provided a unique and exciting setting to test nowcasting systems in mountainous terrain during winter weather conditions. The ABOM method blends extrapolations in time of recent local observations with numerical weather predictions (NWP) model predictions to generate short-range point forecasts of surface variables out to 6 h. The relative weights of the model forecast and the observation extrapolation are based on performance over recent history. The average performance of ABOM nowcasts during February and March 2010 was evaluated using standard scores and thresholds important for Olympic events. Significant improvements over the model forecasts alone were obtained for continuous variables such as temperature, relative humidity and wind speed. The small improvements to forecasts of variables such as visibility and ceiling, subject to discontinuous changes, are attributed to the persistence component of ABOM.