Editorial Type:
Article
Article Type:
Research Article

A Preliminary Survey of Rear-Flank Descending Reflectivity Cores in Supercell Storms

Erik N. Rasmussen Cooperative Institute for Mesoscale Meteorological Studies, University of Oklahoma, Norman, Oklahoma

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Jerry M. Straka School of Meteorology, University of Oklahoma, Norman, Oklahoma

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Matthew S. Gilmore Department of Atmospheric Sciences, University of Illinois at Urbana–Champaign, Urbana, Illinois

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Robert Davies-Jones National Severe Storms Laboratory, Norman, Oklahoma

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Print Publication:
01 Dec 2006
DOI:
https://doi.org/10.1175/WAF962.1
Page(s):
923–938
Restricted access

Abstract

This paper develops a definition of a supercell reflectivity feature called the descending reflectivity core (DRC). This is a reflectivity maximum pendant from the rear side of an echo overhang above a supercell weak-echo region. Examples of supercells with and without DRCs are presented from two days during the Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX), as well as one day with tornadic high-precipitation supercell storms in central Kansas. It was found that in all cases, tornado formation was preceded by the descent of a DRC. However, the sample reported herein is much too small to allow conclusions regarding the overall frequency of DRC occurrence in supercells, or the frequency with which DRCs precede tornado formation. Although further research needs to be done to establish climatological frequencies, the apparent relationship observed between DRCs and impending tornado formation in several supercells is important enough to warrant publication of preliminary findings.

Corresponding author address: Erik Rasmussen, P.O. Box 267, 50742 Bear Run Dr., Mesa, CO 81643. Email: ras@ou.edu

Abstract

This paper develops a definition of a supercell reflectivity feature called the descending reflectivity core (DRC). This is a reflectivity maximum pendant from the rear side of an echo overhang above a supercell weak-echo region. Examples of supercells with and without DRCs are presented from two days during the Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX), as well as one day with tornadic high-precipitation supercell storms in central Kansas. It was found that in all cases, tornado formation was preceded by the descent of a DRC. However, the sample reported herein is much too small to allow conclusions regarding the overall frequency of DRC occurrence in supercells, or the frequency with which DRCs precede tornado formation. Although further research needs to be done to establish climatological frequencies, the apparent relationship observed between DRCs and impending tornado formation in several supercells is important enough to warrant publication of preliminary findings.

Corresponding author address: Erik Rasmussen, P.O. Box 267, 50742 Bear Run Dr., Mesa, CO 81643. Email: ras@ou.edu

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