The purpose of this project is to assess heavy precipitation events that occur within the islands of Hawaii by using numerical modeling. Weather forecasts of precipitation over the Hawaiian Islands have proven to be difficult due to the steep mountainous terrain. Flash flooding occurs during significant synoptic patterns via mechanical forcing of low-level moisture over the mountains, and the mountains act as a convergence zone allowing moisture accumulation and sustained precipitation along the mountainsides. The National Weather Service (NWS) Honolulu Forecast Office (HFO) and NWS Pacific Region Headquarters (PRH) are particularly interested in improving flash flood prediction. Specifically, we will be performing sensitivity tests on the Weather Research and Forecasting model (WRF) to determine how well the model forecasts flash flood events. Case studies, specifically related to flash flood events will be chosen during the Hawaiian cool season (October 2003-April 2004) and examined. The research team includes a first time collaboration between the University of Hawaii and Howard University as well as the NWS HFO and NWS PRH.