Prediction of central Arizona convection. Part I: evaluation of the NGM and Eta model precipitation forecasts

Abstract

The NGM precipitation forecasts showed little skill for events in which heavy precipitation was observed over Phoenix, Arizona. Selected events during the SWAMP period were simulated using the Eta model. Qualitative comparisons of the Eta model's precipitation forecasts with lightning data and satellite imagery suggest that the model has little skill over Arizona during the warm season. Nocturnal heavy precipitation over the lower deserts of central Arizona is nearly always preceded by afternoon convection over the mountains to the north and east. The convection over the mountains was absent in the model. -from Authors