Tropical Cyclones and Drought Amelioration in the Gulf and Southeastern Coastal United States

Abstract

Precipitation from land-falling tropical cyclones (TCs) has a significant hydroclimatic influence in the southeastern United States, particularly during drought years. The frequency with which TCs ended drought conditions was examined for southeastern coastal states from Texas to North Carolina during 1895-2011. The region was divided into the Gulf Coast states (GCS) and the southeastern Atlantic coast states (ACS). The spatiotemporal patterns of tropical cyclone drought busters (TCDBs) were analyzed. Larger-scale ocean-atmosphere influences on TCDBs were examined using chi-squared analysis. The ACS experienced TCDBs more frequently and farther inland compared to the GCS. The number of TCDBs has significantly increased with time in the ACS. TCDBs numbers in the GCS did not exhibit significant increases, but the area alleviated of drought conditions increased significantly in the last 117 years. The dominant larger-scale oceanatmosphere forcing of TCDBs was a combination of a warm Atlantic Ocean ABSTRACTPrecipitation from land-falling tropical cyclones (TCs) has a significant hydroclimatic influence in the southeastern United States, particularly during drought years. The frequency with which TCs ended drought conditions was examined for southeastern coastal states from Texas to North Carolina during 1895-2011. The region was divided into the Gulf Coast states (GCS) and the southeastern Atlantic coast states (ACS). The spatiotemporal patterns of tropical cyclone drought busters (TCDBs) were analyzed. Larger-scale oceanatmosphere influences on TCDBs were examined using chi-squared analysis. The ACS experienced TCDBs more frequently and farther inland compared to the GCS. The number of TCDBs has significantly increased with time in the ACS. TCDBs numbers in the GCS did not exhibit significant increases, but the area alleviated of drought conditions increased significantly in the last 117 years. The dominant larger-scale ocean-atmosphere forcing of TCDBs was a combination of a warm Atlantic Ocean [positive Atlantic multidecadal oscillation index (AMO1)] and weak westerlies [negative North Atlantic Oscillation index (NAO2)]. AMO1 leads to an increase in the number of TCs throughout the North Atlantic basin, and NAO2 increases the likelihood of TC landfall by controlling the steering of TCs toward the southeastern United States.

A systematic assessment of drought termination in the United Kingdom

“…Mo, 2011;Kam et al, 2013;Maxwell et al, 2013;Patterson et al, 2013) have typically considered drought termination to be instantaneous. There are two notable exceptions: Bonsal et al (2011) subdivided drought into six stages, one of which is the concept of drought termination as a phase considered herein, and Nkemdirim and Weber (1999) expressed the concept of a rate of drought termination using Palmer Drought Severity Index units over time.…”

Reconciling droughts and landfalling tropical cyclones in the Southeastern United States

“…There are however a few studies that have specifically looked at the role of the landfalling TCs in mitigating SeUS droughts (Maxwell et al 2012(Maxwell et al , 2013; Ortegren and Maxwell 2014). These studies variously conclude that there are "tropical cyclone drought busters" which mitigate prevailing droughts in the SeUS.…”

The potential role of land cover on secular changes of the hydroclimate of Peninsular Florida

“…1 It is one of the wettest regions of the continental US 2 that also experiences a fair share of extreme wet events from land falling tropical cyclones. [3][4][5] Florida, owing to its relatively mild climate has witnessed an explosive growth in its population in the twentieth Century, expanding at 20-80% per decade. 6 This high growth rate was stymied slightly by the great recession in the first decade of the new century, and the population is now anticipated to reach 23 million by 2030.…”