Practically perfect hindcasts of severe convective storms


This study presents and examines a modern climatology of U.S. severe convective storm frequency using a kernel density estimate to showcase various aspects of climatological risk. Results are presented in the context of specified event probability thresholds that correspond to definitions used at the NOAA/NWS’s Storm Prediction Center following a practically perfect hindcast approach. Spatial climatologies presented herein are closely related to previous research. Spatiotemporal changes were examined by splitting the study period (1979–2018) into two 20-yr epochs and calculating deltas. Portions of the southern Great Plains and High Plains have seen a decrease in counts of tornado event threshold probability, whereas increases have been documented in the middle Mississippi River valley region. Large hail, and especially damaging convective wind gusts, have shown increases between the two periods over a majority of the CONUS. To temporally showcase local climatologies, event threshold days are shown for 12 select U.S. cities. Finally, data created and used in this study are available as an open-source repository for future research applications.

Bulletin of the American Meteorological Society, 101, E1259-E1278