Authors: Todd Moore*, Towson University
Topics: Climatology and Meteorology, Physical Geography, Hazards, Risks, and Disasters
Keywords: Tornado climatology, instability, wind shear, humidity
Session Type: Paper
Presentation File: No File Uploaded
Tornadoes are among the deadliest and costliest natural hazards in the United States. Understanding when and where they occur improves risk estimation along with risk preparation and communication efforts. A so-called eastward shift in tornado activity in the United States, whereby tornado counts are decreasing in portions of the Great Plains and increasing in portions of the Southeast and Midwest, has been recently demonstrated with regional trends and differences of gridded tornado counts and densities between periods. Whether this shift is linked to a mode of climate variability or is a sign of longer-term changes to the climatology of atmospheric conditions is uncertain, although there is evidence that the significant storm parameter (a composite of instability and wind shear parameters) has trended down in the Great Plains and up in the Southeast/Midwest, along with tornado counts. Herein, I present regional and seasonal climatologies of individual tornado ingredients (instability, shear, and low-level moisture) in the Great Plains and Southeast/Midwest. I also present changes to the regional and seasonal mean states of these ingredients.