Predicting the influence of observations on 3-7 day forecasts


Since 1999, the Ensemble Transform Kalman Filter (ETKF) adaptive observing strategy has been used in Winter Storm Reconnaissance (WSR) programs to identify locations for dropwindsonde deployment, in order to improve 1-3 day forecasts. The ETKF has shown promise in being able to predict the error reducing effect of observations over this period. The primary goal of this NOAA THORPEX project is to extend the ETKF to 3-7 days, and assess whether it is capable of predicting the reduction of forecast error variance in the winter storm track due to rawinsonde and/or dropwindsonde observations. In parallel, the propagation of the effects of observations on NCEP GFS forecasts beyond 3 days is being assessed. Preliminary results and ideas will be presented.

Sharan Majumdar