Examining Pacific and Atlantic Hurricane Stage Duration and Length Since 1980

Abstract:

Examining Pacific and Atlantic Hurricane Stage Duration and Length Since 1980

Cassidy Wachtel and Melissa L. Godek

Department of Earth and Atmospheric Sciences, State University of New York College at Oneonta, New York 13820

Abstract:

Each year hurricanes impact thousands of people and over time changes in hurricane characteristics, such as intensity and frequency, have been identified. This study aims to examine changes in hurricane stage duration and track length of West Atlantic and eastern North Pacific hurricanes between 1980 and 2013. Category 2 through 5 hurricanes are analyzed as they evolved through the full life cycle of a hurricane (tropical depression to tropical storm to category). The NOAA National Ocean Service hurricane reanalysis datasets are used to identify 286 storms which are statistically analyzed by category for 1) temporal changes in stage duration with time and 2) temporal changes in stage track lengths with time. NOAA Earth System Research Laboratory daily mean composites of variables such as vertical wind shear and sea surface temperatures are then examined to explain the temporal tendencies that may be related to climate change. Preliminary results indicate that category 2, 4 and 5 storms experienced an overall decrease in stage duration since 1980. For storms of these magnitudes, generally more rapid intensification to category has occurred over time. Contrarily, increased stage duration is detected for hurricanes that reached category 3 status, showing that these storms have strengthened more slowly with time. In all categories, a few unique cases occurred that exhibited stage durations greater than 1 standard deviation from the mean of the long term trend. These cases require further scrutiny for the environmental conditions that might explain the anomalous departures.

Keywords: Hurricanes, West Atlantic Ocean, North Pacific Ocean, Storm Tracks, Tropical Storm, Tropical Depression, Hurricane Stage