Abstract
Atmospheric soundings are analyzed to identify relationships between atmospheric conditions and high percentages of positive cloud-to-ground (CG) lightning in 67 warm-season thunderstorms over southern Louisiana and extreme southern Mississippi. The goal of this study is to determine threshold values of sounding parameters that could be used to predict or nowcast positive lightning. Overall, few relationships are found between these sounding calculations and percentages of positive lightning. The parameters that showed a weak correlation to positive lightning in both forecasting and nowcasting contexts are the 850-500 millibar wind shear, the Bulk Richardson shear, the Severe Weather Threat (SWEAT) Index, and the Energy-Helicity Index. While these weak correlations may indicate the direction of future research into wintertime positive lightning, the conclusion of this study is that atmospheric soundings cannot be used to predict high percentages of positive CG lightning in warm-season thunderstorms.
Heggen, Paul Michael (2000). Meteorological characteristics associated with warm-season positive lightning events. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2000 -THESIS -H43.