Seasonal Precipitation Forecast Over Morocco

Abstract

Interannual variability of precipitation is a challenge for water management in semiarid Morocco, where droughts are common and take a heavy toll on agricultural production. The question of forecast potential for winter and spring rainfall is therefore crucial for the country. As an addition to dynamical seasonal predictions, taking the case of the Oum Er Rbia watershed, the present study builds simple statistical forecasting models for Morocco's winter and spring precipitation, making use of oceanic forcing of atmospheric circulation. Previous results on the teleconnections between North Atlantic wintertime circulation and lagged ocean surface temperatures are confirmed. Based on a careful identification and selection of predictors, about 35–40% of interannual variability of precipitation may be robustly predictable with a lead time of 1 month.