9318491 Horel Recent studies have shown that the National Meteorological Center's regional forecast model, known as the "ETA" model, does poorly in predicting heavy precipitation outbreaks over central Arizona during the summer. The principal investigators believe that this may be due to the way in which certain physical processes over complex terrain are handled in the model. Accordingly, they will undertake a systematic evaluation of the skill of this model over the western United States as a function of synoptic weather situation and season. They plan to employ observations from a series of recent field experiments, the Southwest Area Monsoon Project (SWAMP), in this part of the study. In addition, they will evaluate the ETA model's physical parameterizations in regions of complex terrain. In carrying out this project, the PIs will work closely with personnel at NMC and operational meteorologists in the Western Region of the National Weather Service. This project is supported as part of the NSF/NMC Joint Program in Numerical Weather Prediction. ***
