Hurricanes and Snow

A Common Occurrence in Eastern North Carolina?

Abstract

Snowfall is a rare occurrence in eastern North Carolina, yet rain is plentiful in summer and fall due to thunderstorms and tropical systems. The image of hazards created by both hurricanes and snow are uncommon to North Carolinians due to the climate of the region. However, just as recently as 1999, eastern North Carolina was faced with the challenge of responding first to a hurricane hazard (Dennis and Floyd) then record snowfalls the following winter. The purpose of this paper is to create a baseline-climatology, including frequency, probability, and magnitude, for the occurrence of record hurricane seasons followed by record snow seasons in eastern North Carolina. Results indicate that the occurrence of record rainfall created by a tropical systems followed by a record snowfall in the following is actually fairly common, 18 out of 52 hurricane-snow seasons. The conditional probability of a record snow occurring if a record rain occurs in the preceding hurricane season is 0.95. The authors believe that a physical process does not create the high probability of record rain and snow, but is a fallacy created by the database structure. In particular, a relatively short period of record causes record rain and snow to be likely during the hurricane or snow season. Through an increase of the period of record, a more accurate characterization of a record hurricane-snow season may be possible.