Toward Development of Improved QPE in Complex Terrain Using Cloud-to-Ground Lightning Data: A Case Study for the 2005 Monsoon in Southern Arizona

AbstractThe relationship between convective precipitation and cloud-to-ground (CG) lightning is examined over a study area in southwest Arizona and northwest Mexico. Using seasonal-to-daily and hourly time resolution, the National Climatic Data Center (NCDC) stage IV precipitation product and the U.S. National Lightning Detection Network lightning data have been analyzed with the aim of developing an improved understanding of the relationship between these variables. A Gaussian method of spatially smoothing discrete lightning counts is used to estimate convective rainfall and improve the quality and spatial coverage of radar-derived precipitation in areas of complex terrain. For testing the dependence of the relationship between CG lightning and precipitation, a precipitation “sensor coverage” analysis has been performed. If locations that have poor sensor coverage are excluded, R2 between lightning and precipitation improves by up to 15%. A complementary way to estimate convective precipitation is propos...