Extending Forecast Skill for Winter Storms: Challenges Associated With Improving the Prediction of Major Snow Events and Public/User Response To These Forecasts

One of the major advances in predictive skill over the past 30 years is the improvements involved with forecasting major winter storms. The winter of 2009-2010 saw many storms batter the Unites States, including the historic snowstorms which hit the East Coast in December and February. All of these storms were predicted days in advance with several of the snow storms forecast up to 7 days in advance. Improving these forecasts have undoubtedly affected the view among public sectors and the many who make decisions to protect life and property before and during these storm events. In this presentation, the recent history of the establishment of a forecast process based on numerical models and the fits and starts in the application of this process to forecasting winter storms will be presented, with the recent successes in 2009 and 2010 highlighted to illustrate just how far we have come; and how far we have to go. As noted in the recent NAS report "..Completing the Forecast..." there are many challenges remaining in conveying the certainty and uncertainty for forecasts in general, and specifically for forecasts of extreme events. The presentation will summarize the related requirements for providing probabilistic forecasts from a growing use of ensemble numerical forecast systems, in a manner required for risk management by decision makers and the public. Furthermore a case will be made related to the need to manage the expectations of those in the community who have come to believe that the meteorological community can forecasts all of these events days in advance with a uniform level of skill. Last but not least, the challenges of forecasting the so called light to moderate events will be noted, events that could have larger impact simply given the time of day in which they occur and the narrow regions which they affect; clearly a remaining challenge to those who make the forecasts and to those who make decisions based on them.