A Climatology of High-Wind Events Associated with Post-Tropical Cyclones in the United States

• Main Author: Gilliland, Joshua M.
• Format: Others
• Published: TopSCHOLAR® 2011
• Subjects: GIS; tropical cyclones; convective high winds; nonconvective high winds; Atmospheric Sciences; Climate
• Online Access: http://digitalcommons.wku.edu/theses/1074; http://digitalcommons.wku.edu/cgi/viewcontent.cgi?article=2077&context=theses

During 1951-2009, 47% of all tropical systems (TSs) within the Atlantic Basin transitioned to post-tropical (PTC) extratropical classification. These systems have shown the capability of producing hurricane-force winds and gusts for portions of the eastern United States. This study provides a climatological foundation for high-wind observations that were contributed from PTCs. In this study, 76 PTC systems were identified and tracked using six hourly observations from the National Hurricane Center’s HURDAT dataset. Mean wind radii buffers were calculated and used to determine the high-wind observations attributed by PTCs. High-wind climatology was developed by using hourly surface wind data from the National Climatic Data Center (NCDC) and deploying the current NWS high-wind criteria. For this study, the geography and climatology of PTCs and resultant high winds were analyzed using geographic information systems (GIS). Findings show that < 1% (270) of all high-winds events that occur within the U.S. were contributed from PTCs. The highest frequencies were found in three regions: Midwest, Mid-Atlantic, and New England. Due to the low number of high-wind events produced from PTCs, an adjusted wind scale was created by using standard deviations of sustained and gust observations. The goal of this study is determine the contribution of high winds from PTCs, with the aim of improving our understanding of the hazardous outcomes of such events.