Observations of a severe thunderstorm that spawned a large F3 tornado near Almena, Kansas, on 3 June 1999 showed remarkably few cloud-to-ground lightning (CG) flashes. During a 4.5-h lifetime, in which the storm went from low-precipitation supercell to classic supercell and back, there were just 17 CG flashes. The low CG flash rate highlights the fact that accurate assessments of storm intensity cannot reliably be made using CG lightning flash data alone.
The CG rates for the Almena storm occurred despite the large tornado and baseball-sized hail at the surface. The rates were considerably less than the smallest documented in prior research on CG lightning in violent tornadic storms. In contrast, the data from a portable detector showed that total lightning rates were large enough to suggest the storm was very severe. Total lightning rates during the large tornado were very large-approximately 100/min.
One reason for the lack of CG lightning in the Almena storm may have been its complete isolation from other storm anvils and cirrus clouds. Such clouds, common in severe events, can seed cumulonimbus clouds, alter their microphysical properties, and possibly enhance their precipitation and CG lightning rates.
This study suggests the desirability of obtaining new total flash rate observations from geostationary satellites.-E. W. MCCAUL JR. (UNIVERSITIES SPACE RESEARCH ASSOCIATION), D. E. BUECHLER, S. HODANISH, AND S. J. GOODMAN. "The Almena, Kansas, Tornadic Storm of 3 June 1999: A Long-lived Supercell with Very Little Cloud-to-Ground Lightning," appearing in the February Monthly Weather Review.
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