Improving weather forecast over east Africa through WRF-4DVAR data assimilation technique

In the present study using the Weather Research Forecasting (WRF) and 4DVar data assimilation technique, recent heavy rainfall that occurred over Dar Es Salaam on the 21stDecember; 2011 has been investigated. Three experiments have been conducted with the WRF model and 4D-Var data assimilation technique to test the e_ect of horizontal resolution and cumulus parameterizations on simulating heavy rainfall. Another experiment was conducted to test if there is an added value to use 4D-Var data assimilation technique on WRF model. The results show that high horizontal resolution is needed for better weather forecasting with choice of better cumulus parameterizations schemes. Also the results show that for improving daily weather forecasting, Tanzania Meteorological. Agency (TMA) needs the use of 4D-Var data assimilation technique for the daily operations.