Total lightning characteristics of ordinary convection
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Twenty-two isolated, non-severe, warm season thunderstorms (ordinary thunderstorms) were examined to test possible correlations between three-dimensional lightning flash characteristics and the complex evolution of the microphysical and kinematic processes involved in the electrical development of thunderstorms. Nine of the thunderstorm cases examined occurred within range of Vaisala Inc.'s Dallas-Fort Worth (DFW) Lightning Detection and Ranging (LDAR) network and the other thirteen cases occurred within range of the Texas A&M University Houston LDAR Network. Cloud-toground (CG) flash data were obtained from the National Lightning Detection Network (NLDN). The kinematic and microphysical properties of each convective cell were inferred from level II Weather Surveillance Radar 1988-Doppler data. Lightning properties were compared to radar reflectivity, Vertically Integrated Liquid, Severe Hail Index, and Vertically Integrated Ice (VII) (i.e. the measure of the precipitation ice water content in and above the mixed phase (-40°C < T < -10° C zone). In addition, total lightning (intra-cloud (IC) and CG) characteristics were compared against CG lightning characteristics to determine if total lightning data provide stronger correlations to convective intensity and state (i.e., developing, mature, dissipating) than CG lightning data alone. The results show that VII is well correlated to the total flash rate with r2 values of 0.45 and 0.81 for Houston and Dallas cases, respectively, whereas CG flashes show much weaker correlations to VII. The cases also follow the conventional model of lightning within ordinary storms with IC dominating over CG lightning in the initial stages of convective development. An average of 19 IC flashes occur before the first CG flash with an average lead-time between the first IC to the first CG of 12 minutes. Flash heights showed little correlation to VII, which is in disagreement with past studies suggesting that strong correlations exist between flash heights and storm intensity. Integration of the results from this study into an operational forecast setting could lead to improvements in the nowcasting of lightning threats using radar, numerical weather prediction via assimilation of total lightning data, and the nowcasting of severe weather and lightning hazards to aviation.
Motley, Shane Michael (2006). Total lightning characteristics of ordinary convection. Master's thesis, Texas A&M University. Available electronically from