Adding Value to the Guidance Beyond Day Two: Temperature Forecast Opportunities Across the NWS Southern Region

Previous investigation by the authors showed an increase from 2007 to 2009 in the frequency of temperature Forecast Opportunities, days for which the maximum and/or minimum temperature MOS Guidance is in error by ten or more Fahrenheit degrees, across the NWS Southern Region. Such Opportunities often occur during the cool half of the year, especially before and after frontal passages. However, a decrease in the frequency of temperature Forecast Opportunities was noted during the winter of 2009-2010. This presentation will review the results of an examination of that decrease. Cooler than normal temperatures, typically associated with El Niño, prevailed over the Southern U.S. during that period. Day-to-day temperatures were less variable, explaining the reduction in Forecast Opportunities. A closer look at some prolonged Forecast Opportunities cases, when more than one consecutive day of the MOS Guidance was in error by ten or more Fahrenheit degrees, showed a relationship between the nature of the passage of Arctic/Polar Fronts across the region.