Extended Abstract (892K)4.6
Electrical and polarimetric radar observations of a HP supercell on 29 May 2004 during TELEX
Clark D. Payne, CIMMS/Univ. of Oklahoma, Norman, OK; and T. J. Schuur, W. D. Rust, D. R. MacGorman, M. I. Biggerstaff, K. M. Kuhlman, E. C. Bruning, and N. R. Lund
In the spring of 2004, the National Severe Storms Laboratory hosted the Thunderstorm Electrification and Lightning Experiment (TELEX) in central Oklahoma. The primary goal of TELEX was to collect datasets that might be used to examine the concurrent kinematic, microphysical, and electrical structures of a variety of warm season precipitation systems. Datasets available for most TELEX events include 3-D lightning mapping array (LMA), polarimetric KOUN WSR-88D radar, dual-Doppler SMART-R radar, and balloon-borne electric field meter data. In this study, we examine the combined kinematic, microphysical, and electrical structures of a high precipitation (HP) supercell that passed through the TELEX domain from approximately 2330 UTC (29 May 2004) through 0330 UTC (30 May 2004). Over its lifetime, this storm produced 18 F0 to F3 intensity tornadoes.
Previous work has shown that supercells often exhibit a feature known as a lightning hole, where a region of minimal lightning activity is found to be located in the storm updraft. They are usually only co-located with strong updrafts. The primary goal of this study it to investigate whether a relationship exists between the 29-30 May 2004 supercell lightning hole, as observed by the LMA, and concurrent microphysical and kinematic features, as derived from the KOUN WSR-88D polarimetric radar and SMART-R radars respectively. In particular, recent polarimetric observations of supercell storms (including observations in the 29-30 May 2004 supercell storm) have revealed the existence of intermittent low-level, hook-shaped curtains of high differential reflectivity (ZDR) and mid-level rings of low correlation coefficient (HV) in the region surrounding intense updrafts. In this study, the LMA data are analyzed in the context of the microphysical information provided by the polarimetric radar data and kinematic information provided by the dual-Doppler radar data to investigate whether the combined dataset provides insight into the location, intensity, and evolution of the lightning hole.
The 29-30 May 2004 supercell was found to have an inverted electrical structure and, contrary to recent research, to be dominated by negative cloud-to-ground lightning. Polarimetric radar data are therefore also used to investigate possible microphysical conditions that might be responsible for these features. Finally, in order to compare the results of this study to previous work, total flash rates (almost 600 per minute) are correlated with graupel and updraft volumes.
Session 4, Lightning and Electrical Processes in Convective to Mesoscale Storms
Tuesday, 22 January 2008, 3:30 PM-5:45 PM, 222
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