A Comparative Study of Two Extreme Cases Hit Egypt in January 2008 and 2009 Using WRF Different Convective Schemes

Abstract

Heavy rainfall associated with severe flash floods cause loss of life and property. Forecasting of these severe weather events is highly essential because of their impacts on infrastructure and life over Egypt. Sinai Peninsula and sometimes southern parts are more affected by frequent heavy rainfall during the last decade in January. Early warning of these events will contribute avoiding destructive effects. WRF model was run with three convective cumulus schemes (Kain-Fritsch, Grell-Devenyi and Betts-Miller- Janjic) to simulate rainfall during January 14-19 in 2008 and 2009 over Egypt. The run of the model was done based on two nest domains at horizontal resolution of 27 km for mother domain and 9 km for nest domain to establish the best scheme that simulates rainfall better than the other two schemes during the period of study over the country. After comparing rainfall from these convective schemes with corresponding daily-clim reanalysis, Grell among the chosen cumulus convective schemes was found to give better results compared to other cumulus schemes along the period of the study. Synoptic study of these two cases was conducted. It is found that the extreme rainfall events were due to amalgamation between tropical and mid latitudes pressure systems.