Evaluation of data assimilation on numerical weather prediction for Egypt

The objective of this work is to evaluate the use of data assimilation in numerical weather prediction for Egypt. Effects of different data assimilation options were studied for different weather regimes and at locations with different observation site densities. Effects on accuracy at the observational-data-void areas and at the locations with complex terrain were of prime concern. Five sets of simulations were performed based on different nudging options in summer and in winter. Four sets of observational stations were selected for data sampling locations based on their relative positions with respect to the assimilated observations. Errors were computed for the four observation sets. The best nudging options and areas with maximum effect on error were identified.