Climatology of potentially severe convective environments from reanalysis

This study establishes a U.S. climatology of potentially severe convective environments for the period 1979--2009 using reanalysis data. Examinations of variability of significant severe weather environments are presented for five active severe weather regions in the U.S. Regional comparisons illustrate significant environments have changed little over the period of record. Significant severe environments are then verified by significant severe weather reports to ensure climatologies presented herein are indeed representative of observations. Reports indicate that environments calculated by reanalysis tend to overestimate the actual distribution of reports, likely due to the absence of accounting for a lifting mechanism. On average, reanalysis calculated significant severe weather environments closely mimic the annual cycle of significant severe weather reports. Additionally, analysis the Arctic Oscillation's impact on significant severe weather reports in the Midwest also conducted. While the Arctic Oscillation alone shows little skill in predicting significant severe weather reports, further studies should incorporate additional teleconnection indices, as many factors must work in concert to produce a significant severe weather event.