William Koshak (ST11) co-authored this paper which was accepted for publication on 10/31/23 in the American Meteorological Society (AMS) journal Monthly Weather Review. The relation of lightning to El Nino Southern Oscillation (ENSO) and the Madden-Julian Oscillation (MJO) is examined. In the study, 2003–2016 cloud-to-ground (CG) lightning observations over the continental U.S. are modeled using Poisson Regression (PR) that relates CG flash count data to Convective Available Potential Energy (CAPE) and precipitation values. The PR models more accurately captured the dependence of flash count on the environmental factors compared to previous models. The PR model with the best performance used log(CAPE), log(CAPE)2, log(Precipitation), and log(Precipitation)2 terms as predictors. Overall, daily and seasonal variability in CG flash count was represented well. Applying the PR model to construct a lightning proxy for a longer period (1979–2021) revealed that it was not related to the active MJO phases during June-September. However, ENSO was associated with anomalous PR lightning flash patterns. Hence, ENSO may be a useful (winter – spring) predictor of CG lightning activity, valuable for protecting public safety and for better-understanding increased risk of lightning-caused wildfires and thunderstorm-related impacts.
Read the paper at: https://journals.ametsoc.org/view/journals/mwre/151/12/MWR-D-23-0157.1.xml.
