An Analysis of Southern U.S. Ice Storm Frequency from 2000-2009

The Southern Climate Impacts Planning Program (SCIPP) is a climate research program that focuses on helping the public improve planning for weather and climate-related disasters. SCIPP focuses on the high frequency of hazardous weather events, including extremes in precipitation. Over the past several years, SCIPP has speculated that there has been an increase in the number of ice storms within the region each winter. This paper analyzes trends in ice storm frequency and intensity for the years 2000-2009 using data from the National Climatic Data Center's Storm Events and Storm Data datasets. For this period of study, it was found that an ice storm maximum stretches from southwestern Texas through Oklahoma, northwestern Arkansas, southeastern Kansas and central Missouri. It was also found that there is no consistent trend associated with the number of ice storms, the ice thickness values of recorded ice storms, or the number of ice storm catastrophes over the last ten years. Ice storm frequency was also briefly compared to atmospheric signals and El Nino-Southern Oscillation (ENSO) events. This project also indentified discrepancies in ice storm reporting across National Weather Service office boundaries as evidenced through Geographic Information Systems mapping. This project provides preliminary results that can be incorporated into more extensive studies to create national criteria for documenting ice storms.