Predictive Skill of the Seasonal CFSv2 Forecasts for Extreme Weather Patterns in the Southern Plains

The Climate Prediction Center (CPC) of the National Weather Service (NWS) makes seasonal forecast outlooks using the Climate Forecast System version 2 (CFSv2) numerical model at 1-month and 3-month temporal ranges. These forecasts typically discuss the wide range of climate indexes that are already well known. The relationship between climate and weather is not very black and white, but this study attempts to use an upgraded modeling system such as the CFSv2 to study this relationship.

The past six years of tornado data in the Southern Plains of the United States were examined in order to determine trends in the number of tornadoes per month. Disruptions in the number of tornadoes were identified in order to select a relevant time span to study. The tornado count for April 2013 greatly differed from the previous five years. Identifying a time span with anomalously low tornadic activity may aid in identifying differences in synoptic patterns that exist in order to better forecast an active severe weather pattern across the U.S.

Many studies have been done in order to determine what climate triggers are indicative of tornado outbreaks and thus what synoptic patterns are indicative of active severe weather. This study will focus on the ability of the CFSv2 to predict a proper environment for active and non-active severe weather patterns based on prognostic and convective variables. Comparisons between an active (April 2012) versus non-active (April 2013) severe weather pattern are described.