A Detailed Climatology of Central North Carolina Tornadoes

Past experience shows that the occurrence, frequency, and intensity of tornadoes varies considerably across North Carolina. North Carolina's mid-latitude location with its frequent exposure to the westerlies and sources of instability, as well as the proximity of the Atlantic Ocean and the Gulf of Mexico, provides many of the ingredients for the production of severe convection including tornadoes. An improved understanding of the distribution of tornadoes along with the environmental conditions, convective mode, and radar characteristics associated with these events, would improve the anticipation of tornadoes and the warning decision making process of forecasters.

A tornado climatology of the County Warning Area (CWA) covered by the National Weather Service (NWS) office in Raleigh, North Carolina in central North Carolina will be presented. An initial climatology will be completed across all of North Carolina focusing on the date, location, intensity, and track of tornadoes from 1950 to 2014. In addition, a more detailed analysis of tornadoes across central North Carolina in the Raleigh CWA will be completed. This analysis will focus on tornadoes subsequent to the deployment of the NWS Doppler radar in Raleigh (KRAX) in 1994 and extend up through 2014. These cases will be examined in much greater detail, focusing on the near-storm mesoscale environment utilizing RUC/RAP proximity soundings, radiosonde observations, and surface observations along with archive level-II radar data. Each event will be classified using common severe storm characteristics such as synoptic pattern including tropical cyclones, convective storm mode, and near-storm convective environment. In addition, other characteristics such as the time of tornado occurrence (daytime vs. nighttime) and the number of injuries and fatalities will be examined. By better understanding previous tornadic events in central North Carolina, it is hoped that forecast methods can be improved to help forecast and communicate the risk of tornadoes and contribute to the NWS Weather-Ready Nation initiative.