Characteristic Paths of Extratropical Cyclones that Cause High Wind Events in the Northeast United States

Tuesday, 16 December 2014
James F Booth, CUNY City College, New York, NY, United States, Harald E Rieder, University of Graz, Wegener Center for Climate and Global Change and IGAM/Institute of Physics, Graz, Austria, Dong Lee, Lamont -Doherty Earth Observatory, Palisades, NY, United States and Yochanan Kushnir, Columbia Univ, Palisades, NY, United States
This study analyzes the association between wintertime high wind events (HWEs) in the northeast United States US and extratropical cyclones. Sustained wind maxima in the Daily Summary Data from the National Climatic Data Center’s Integrated Surface Database are analyzed for 1979-2012. For each station, a Generalized Pareto Distribution (GPD) is fit to the upper tail of the daily maximum wind speed data, and probabilistic return levels at intervals of 1, 3 and 5-years are derived from the GPD fit. At each interval, wind events meeting the return level criteria are termed HWEs. The HWEs occurring on the same day are grouped into multi-station events allowing the association with extratropical cyclones, which are tracked in the European Center for Medium-Range Weather Forecast ERA-Interim reanalysis. Using hierarchical clustering analysis, this study finds that the HWEs are most often associated with cyclones travelling from southwest to northeast, usually originating west of the Appalachian Mountains. The results show that a storm approaching from the southwest is four times more likely to cause strong surface winds than a Nor’easter. A series of sensitivity analyses confirms the robustness of this result. Next, the relationship between the strength of the wind events and the corresponding storm minimum sea level pressure is analyzed. No robust relationship between these quantities is found for strong wind events. Nevertheless, subsequent analysis shows that a relationship between deeper storms and stronger winds emerges if the analysis is extended to the entire set of wintertime storms.