Evaluation of Real-Time Forecasts During the African Monsoon Multidisciplinary Analysis 2005 DRY Runs

During the period August 22nd – September 2nd 2005 the Weather and Forecasting Research (WRF) model is used in a forecast mode for prediction of the West African Monsoon. A nested domain with the parent domain covering the region from 45W-15E and the Equator the 27N will be used. The WRF grid spacing of 24 km is used for the parent domain and 8 km for the nested domain. The initial and boundary conditions are derived from the National Center for Environmental Prediction (NCEP) Global Forecast System (GFS) model. . As a means of validating these simulations, we rely on concurrent hydrometeorological ground based raingauges, radiosonde,gues and satellite observations. The model's ability to capture large-scale and local scale features will be evaluated as well. In particular, the evolution of long-lived mesoscale convective systems, African easterly waves, the African and tropical easterly jets will be compared to observations and the GFS data. Model simulated rain characteristics will be compared to space borne products on a 6-hour basis. A number of other variables as defined by the AMMA forecasting committee will also be evaluated. The goal is to characterize the diurnal cycle of precipitation in West Africa and to develop an understanding of the physical processes that determine the monsoon hydrometeorology in this region. These results and the implications for real time forecasts during the AMMA 2006 special observing period will be presented.