Assessment and Prediction of Seasonal Tornado Activity

This paper will provide a status update on linked efforts to assess and predict regional tornado activity over monthly to seasonal time scales. The assessment technique provides regional distributions of tornado days relative to climatological means. Correlation of these tornado-day anomalies to observed anomalies in atmospheric forcing allows us to build regression models that are then applied to NCEP Climate Forecast System (CFS) forecasts. This statistical-dynamical technique is complemented by a high-resolution (convective-storm–permitting) dynamical downscaling technique, in which the Weather Research and Forecasting (WRF) model is integrated daily using initial and boundary conditions from the CFS. Our techniques are demonstrated for the warm seasons of 2011 and 2012.