Selected Cases of the RSM-based NCEP Short-Range Ensemble Forecasting (SREF)

Case 2: 1997 Southern US Heavy Rain (02/12/97 - 02/13/97)

For this Southern US heavy rain case (12Z, 02/11/97), the maximum probability of precipitation amount exceeding 2.0"/12hr (24-36hr, upper right figure), derived from a 5-member RSM-based ensemble (with regional bred mode), agrees quite well with the observed rainfall center (in 24hr-accumulation, lower figure). However, the individual forecasts show variability in location (e.g., the isohyet of 2.0"/12hr, upper left figure).