Regional spatiotemporal relationships between cloud-to-ground (CG) lightning and precipitation have been found throughout the US, with much of the research focused on the Midwest, the Southwest, and Florida. These studies show promise in improving the understanding of the CG lightning-precipitation relationship, which could lead to other ways of using CG lightning as a tool to aid meteorologists in better understanding convective events and the precipitation they produce. For instance, CG lightning could be used as a tool for precipitation quantification and identification, especially in areas with inadequate radar coverage, if the relationship between CG lightning and precipitation is better understood. It is important to investigate CG lightning-precipitation relationships by region, since studies show these relationships are sensitive to local climatic conditions, such as the contrast between the coastal areas of the Gulf Coast and the more arid, interior regions of the US. The southeast US receives more precipitation and CG lightning than any other region of the US, but, with the exception of Florida, is not an area where CG lightning-precipitation relationships have been adequately investigated.

This research will present an analysis of the seasonal, spatiotemporal distribution of CG lightning relative to precipitation in the lower Mississippi River Valley portion of the southeast US. The study will utilize radar-based 4x4-km precipitation estimates from the NEXRAD multi-sensor precipitation estimator (MPE) and Stage III algorithms, as well as observed cloud-to-ground lightning strikes recorded by the National Lightning Detection Network (NLDN). Precipitation studies in this region could aid in the forecasting of hydrological conditions that would be invaluable to flood control interests in the Mississippi River watershed. In addition, precipitation studies that could reveal precipitation patterns and changes across the region are important for this agriculturally rich region of the US. Like previous studies, the correlation between CG lightning and precipitation is expected to be strongest in the warm season months and with increasing distance from the Gulf Coast. Correlation coefficients will be determined across the study area for each month from January 2001 to December 2007. Understanding the relationship(s) between CG lightning and precipitation could improve a meteorologist's situational awareness of the environment and thus improve their nowcasting ability.