Numerical simulation of the probability distribution function of precipitation over Morocco

A variable resolution version of the global GCM ARPEGE is constructed, so that Morocco has maximum resolution. A 30-year simulation, driven by observed sea surface temperature 1971–2000, is carried out. This paper examines the precipitation over northern Morocco during the extended winter season (from October to March), comparing model simulations with daily values at 14 stations. An approach utilising weather regimes has been adopted. The model is successful in representing the frequency and the interannual variability of the regimes. The precipitation over Morocco differs from one regime to another, but the model is not enough rainy along the Atlantic coast in general. The model is too persistent with too long dry spells, but is able to produce heavy rainfall as well as long dry periods in the centre of the area.