THE SEVERE T HUN DERST ORM ELEC TRIFIC A TIO N A N D PRECIPIT A TIO N STUDY
BY TIM O T HY J . L A N G , L. J AY MILLER, M O RRIS W E I S M A N , STEVEN A . RUTLE D GE, LLYLE J . BARKER III, V . N . BRINGI, V . C H A N D R ASEKAR , A N D R E W D E TWILER , N O L A N D O E SKE N , J O H N HELS D O N , CHARLES K N IG H T , PAUL KREHBIEL, W A L T E R A . LY O NS, D O N M A C G O R M A N , ERIK RASMUSSEN, W I L L I A M RIS O N , W . D A VI D RUST , A N D R O N A L D J . T H O M A S
Data from a field project on the Colorado - Kansas border in summer 2000 is helping to improve our understanding of positive cloud-to-ground lightning and low- precipitation storms.
evere thunderstorms, because of their propensity as they exhibit not only a wide range of electrical ac- to injure, kill, and cause extensive property dam- tivity, but also diversity in precipitation type and Sage, are a primary concern to not only weather amount. One of the more intriguing severe storms forecasters but also the public. However, these storms types in this regard is the supercell thunderstorm remain a puzzling scientific and forecasting problem, (Browning 1964). In its most pristine state, a supercell is a unicellular thunderstorm comprised of a single, long-lived, rotating updraft, and it frequently pro- AFFILIATIONS: LANG, RUTLEDGE, BRINGI, AND CHANDRASEKAR— duces large hail, high winds, prolific lightning, and Colorado State University, Fort Collins, Colorado; MILLER, WEISMAN, occasionally tornadoes. While the basic dynamics of AND KNIGH T—National Center for Atmospheric Research, Boulder, supercells seem well understood (e.g., Klemp 1987), Colorado; BARKER—National Weather Service, Lincoln, Illinois; these storms exhibit a wide variety of precipitation DETWILER AND HELSD O N—South Dakota School of Mines and Technology, Rapid City, South Dakota; D OESKEN—Colorado Climate characteristics that are not understood. For instance, Center, Fort Collins, Colorado; KREHBIEL, RISON, AND TH OMAS— supercells have been classified as either low precipi- New Mexico Institute of Mining and Technology, Socorro, New tation (LP; Donaldson et al. 1965; Davies-Jones et al. Mexico; LY O NS—FMA Research, Inc., Fort Collins, Colorado; 1976; Burgess and Davies-Jones 1979; Bluestein and MACGORMAN, RASMUSSEN, AND RUST—National Severe Storms Parks 1983), classic or medium precipitation (MP), Laboratory, Norman, Oklahoma or heavy precipitation (HP; Doswell and Burgess CORRESPONDING AUTHOR: Timothy J. Lang, Department of 1993; Rasmussen and Straka 1998) based on visual Atmospheric Science, Colorado State University, Fort Collins, C O 80523 observations of the cloud and precipitation shafts. E-mail: [email protected] Perhaps the least-understood among these storms are D OI: 10.1175/BAMS-85-8-1 107 LP supercells, which characteristically produce some
In final form 26 March 2004 large hail but little rain. Potentially because of the dry ©2004 American Meteorological Society environment and lack of visible precipitation, the vis- ible cloud below the anvil is a skeleton compared with
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