The paths of extratropical cyclones associated with wintertime high wind events in the Northeast United States

Abstract

This study analyzes the association between wintertime high wind events (HWEs) in the northeast United States 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 1, 3 and 5-years are derived. Wind events meeting the return level criteria are termed HWEs. The HWEs occurring on the same day are grouped into simultaneous wind exceedance dates, termed multi-station events. In a separate analysis, extratropical cyclones are tracked using the ECMWF ERA-Interim reanalysis. The multi-station events are associated with the extratropical cyclone tracks based on cyclone proximity on the day of the event. The multi-station wind events are found to be most often associated with cyclones travelling from southwest to northeast, originating west of the Appalachian Mountains. To quantify the relative frequency of the strong wind associated cyclones, the full set of northeastern cyclone tracks are separated based on their path, using a crosshairs algorithm designed for this region. The tracks separate into an evenly distributed set of four pathways approaching the northeast US: from the due west, from the southwest, nor'easters, and storms starting off coast, north of the Carolinas. Using the frequency of the tracks in each of the pathways, it is shown that the storms associated with multi-station wind events are most likely to approach the northeast US from the southwest