Intense windstorms in the Northeastern United States Frederick Letson1, Rebecca J. Barthelmie2, Kevin I. Hodges3 and Sara C. Pryor1 1Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, New York, USA 2Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York, USA 5 3Environmental System Science Centre, University of Reading, Reading, United Kingdom Correspondence to: F. Letson (
[email protected]), S.C. Pryor (
[email protected]) Abstract. Windstorms are a major natural hazard in many countries. The objective of this study is to identify and characterize iIntense windstorms during the last four decades in the U.S. Northeast are identified and characterizedand determine both the sources of cyclones responsible for these events and the manner in which those cyclones differ 10 from the cyclone climatology. The windstorm detection is based on using the spatial extent of locally extreme wind speeds at 100 m height from the ERA5 reanalysis database. During all the of the top 10 windstorms, wind speeds in excess of their local 99.9th percentile extend over at least one-third of land-based ERA5 grid cells in this high population density region of the U.S.. Maximum sustained wind speeds at 100 m during these windstorms range from 26 to over 43 ms-1, with wind speed return periods exceeding 6.5 to 106 years (considering the top 5% of grid cells 15 during each storm). Property damage associated with these storms, inflation adjusted to January 2020, ranges from $24 million to over $29 billion. Two of these windstorms are linked to decaying tropical cyclones, three are Alberta Clippers and the remaining storms are Colorado Lows.