Climatology of Potentially Severe Convective Environments from the North American Regional Reanalysis

Abstract

This study establishes a U. S. climatology of potentially severe convective environments for the 30-y period 1980-2009 from the North American Regional Reanalysis.  Variability of environments supporting significant severe weather is examined for four active severe-weather regions in the U. S.  Regional comparisons illustrate potentially significant-severe environments varied greatly both spatially and temporally over the 30-y period of record.  The spatial and temporal distributions of significant severe-weather environments and reports are subjectively examined for comparison purposes. While one has to be cautious when linking environments and reports, average calculated significant severe-weather environments show similarities to the annual cycle of significant severe-weather reports.  Additionally, mean center analysis indicates that there is no significant shift in the average position of these environments during the period of record.