Sunday, 22 January 2012
An Investigation of Environmental Factors Leading to Extreme Lightning Flash Rates and IC:CG Ratios
Hall E (New Orleans Convention Center )
Meteorologists and the general public have observed that some thunderstorms produce large lightning flash rates while other storms produce average or below average rates. The ratio of in-cloud (IC) and cloud-to-ground (CG) lightning (IC:CG) also shows large daily variations, variations from storm to storm, and variations during the lifecycle of an individual storm. Williams et al. (2005) examined the relationship between several thermodynamic parameters (i.e. CAPE, Cloud Base Height (CBH), dry bulb temperature (Td)) and flash rate using climatological data over the Continental United States (CONUS).
This paper will examine these relationships using observed data, not climatological values. WeatherBug Total Lightning Network (WTLN) observational data and RUC Model data. The paper focuses on much shorter time spans that Williams et al. (2005), considering daily or less than daily time spans, The study domain also will be much smaller than considered by Williams et al (2005), the region surrounding the Kennedy Space Center.
By focusing on a more localized region and shorter periods, I hope to confirm and refine the relationships between flash rate and thermodynamic parameters described by Williams et al. (2005). If successful, such relationships will help forecasters warn the public of impending major lightning events.