Geophys. Res. Lett., accepted subject to revision.
Michael K. Tippett
International Research Institute for Climate and Society, Columbia University, Palisades, NY
Adam H. Sobel
Department of Applied Physics and Applied Mathematics, Department of Earth and Environmental Sciences, and Lamont-Doherty Earth Observatory, Columbia University, New York, NY
Suzana J. Camargo
Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY.
Monthly U.S. tornado numbers are here related to observation-based monthly averaged atmospheric parameters. This relation captures the climatological spatial distribution and seasonal variation of tornado occurrence, as well as year-to-year variability, and provides a framework for extended range forecasts of tornado activity. Applying the same procedure to predicted atmospheric parameters from a comprehensive forecast model gives some evidence of the predictability of monthly tornado activity.