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Lightning in the Anvils of Supercells. Stephanie A. Weiss, Donald R. MacGorman, and Kristin M. Kuhlman. Why Anvil Lightning?. Scientifically Interesting Lifetime of charge Charging of hydrometeors in the anvil Societal Impacts Ground flashes beneath the anvil Predictability.
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Lightning in the Anvils of Supercells Stephanie A. Weiss, Donald R. MacGorman, and Kristin M. Kuhlman
Why Anvil Lightning? • Scientifically Interesting • Lifetime of charge • Charging of hydrometeors in the anvil • Societal Impacts • Ground flashes beneath the anvil • Predictability Anvil lightning flash example from 26 May 2004 supercell
Overview of Study • Supercell thunderstorms in Central Oklahoma • 22 cases • 2004-2009 • Data sources • Oklahoma Lightning Mapping Array (OK-LMA) • National Lightning Detection Network (NLDN) • KOUN • KTLX • Definition of anvil
Flash Initiation in Core 2236:44 UTC 24 May 2004 2236:44 UTC 24 May 2004
Flash Initiation in Core 2236:44 UTC 24 May 2004 Negative Screening Layer Charge Initiation Positive Storm Charge Negative Storm Charge
Flash Initiation in Anvil: Screening Layer Charge 0107:48 UTC 30 May 2004
Flash Initiation in Anvil: Screening Layer Charge 0107:48 UTC 30 May 2004 Positive Screening Layer Charge Negative Storm Charge
Flash Initiation in Anvil: Reflectivity Maximum 2328:43 UTC 24 May 2004
Flash Initiation in Anvil: Reflectivity Maximum 2328:43 UTC 24 May 2004 Initiation
Ground Flashes beneath Anvil: Rain or Virga 2324:30 UTC 24 May 2004
Flash Initiation in Anvil: Anvil Interaction 2321:45 UTC 29 May 2004 CAPPI at 7km
Flash Initiation in Anvil: Anvil Interaction 2321:45 UTC 29 May 2004 Anvil of Southern Storm Anvil of Northern Storm Initiation
Preliminary Findings • Initiation of Anvil Flashes • Core of storm • Screening layer charge • Reflectivity maximum • Anvil-anvil interaction • Ground Flashes beneath Anvil • Rain • Virga • Anvil below melting/freezing height
Preliminary Findings • Low-top supercells • 2 cold-season cases • No anvil lightning • Polarimetric radar data comparison • No obvious patterns • Helpful in determining freezing level
Acknowledgments • This work was funded by NASA EPSCoR grant #NNX07AV48A • Thank you to Eric Bruning for listening to and discussing my ever-evolving theories. • Thank you to Terry Schuur and Clark Payne for their help in acquiring and processing KOUN radar data. References • Kuhlman, K. M. , D. R. MacGorman, M. I. Biggerstaff, and P. R. Krehbiel (2009), Lightning initiation in the anvils of two supercell storms, Geophys. Res. Lett., 36, L07802, doi:10.1029/2008GL036650.