Intensification of Hurricane Sandy (2012) through extratropical warm core seclusion

AMS Citation:
Galarneau, T. J., C. A. Davis, and M. A. Shapiro, 2013: Intensification of Hurricane Sandy (2012) through extratropical warm core seclusion. Monthly Weather Review, 141, 4296-4321, doi:10.1175/MWR-D-13-00181.1.
Date:2013-12-01
Resource Type:article
Title:Intensification of Hurricane Sandy (2012) through extratropical warm core seclusion
Abstract: Hurricane Sandy's landfall along the New Jersey shoreline at 2330 UTC 29 October 2012 produced a catastrophic storm surge stretching from New Jersey to Rhode Island that contributed to damage in excess of $50 billion—the sixth costliest U.S. tropical cyclone on record since 1900—and directly caused 72 fatalities. Hurricane Sandy's life cycle was marked by two upper-level trough interactions while it moved northward over the western North Atlantic on 26–29 October. During the second trough interaction on 29 October, Sandy turned northwestward and intensified as cold continental air encircled the warm core vortex and Sandy acquired characteristics of a warm seclusion. The aim of this study is to determine the dynamical processes that contributed to Sandy's secondary peak in intensity during its warm seclusion phase using high-resolution numerical simulations. The modeling results show that intensification occurred in response to shallow low-level convergence below 850 hPa that was consistent with the Sawyer-Eliassen solution for the secondary circulation that accompanied the increased baroclinicity in the radial direction. Additionally, cyclonic vertical vorticity generated by tilting of horizontal vorticity along an axis of frontogenesis northwest of Sandy was axisymmetrized. The axis of frontogenesis was anchored to the Gulf Stream in a region of near-surface differential diabatic heating. The unusual northwestward track of Sandy allowed the cyclonic vorticity over the Gulf Stream to form ahead of the main vortex and be readily axisymmetrized. The underlying dynamics driving intensification were nontropical in origin, and supported the reclassification of Sandy as extratropical prior to landfall.
Subject(s):Convective storms, Dynamics, Hurricanes, Mesoscale processes, Extreme events, Tropical cyclones
Peer Review:Refereed
Copyright Information:Copyright 2013 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be "fair use" under Section 107 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Law (17 USC, as revised by P.L. 94-553) does not require the Society's permission. Republication, systematic reproduction, posting in electronic form on servers, or other uses of this material, except as exempted by the above statements, requires written permission or license from the AMS. Additional details are provided in the AMS Copyright Policies, available from the AMS at 617-227-2425 or amspubs@ametsoc.org. Permission to place a copy of this work on this server has been provided by the AMS. The AMS does not guarantee that the copy provided here is an accurate copy of the published work.
OpenSky citable URL: ark:/85065/d7k64jz5
Publisher's Version: 10.1175/MWR-D-13-00181.1
Author(s):
  • Thomas Galarneau - NCAR/UCAR
  • Christopher Davis - NCAR/UCAR
  • Melvyn Shapiro - NCAR/UCAR
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