21st Conf. on Severe Local Storms and 19th Conf. on Weather Analysis and Forecasting/15th Conf. on Numerical Weather Prediction

Wednesday, 14 August 2002: 2:30 PM
Lightning characteristics of two storms observed during STEPS
Andrew G. Detwiler, South Dakota School of Mines & Technology, Rapid City, SD; and J. H. Helsdon, D. V. Kliche, Q. Mo, and T. A. Warner
Poster PDF (314.2 kB)
Several storms observed during the Severe Thunderstorm Electrification/Precipitation Study (STEPS) in 2000 produced cloud-to-ground lightning with predominantly positive polarity. Using a combination of data from the project lightning mapping array, polarimetric radars, in situ aircraft, and surface observing systems, we compare the microphysical and lightning characteristics of two storms. One was an asymmetric MCS, the southern portions of which produced predominantly negative, and northern portions predominantly positive, cloud-to-ground lightning. The other was a much more vigorous tornadic single-cell storm wbich produced intracloud lightning for almost an hour before producing a tornado and predominantly positive cloud-to-ground lightning. Both produced hail with peak sizes between 2 and 3 cm. The microphysical and charge structures differ between the two storms in complex ways which will be discussed in the presentation.

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