On the forecast of cumulative precipitation at subseasonal time-scales over the Sahel

Abstract

The Sahel, which is considered to be amongst the climate sensitive regions for its history of droughts and famine, and excessive precipitation and disease, is also a source for easterly waves, which upon encountering favorable conditions over the Atlantic Ocean, transform into hurricanes. Benefits from the successful forecast of key variables at subseasonal time scales are obvious. We demonstrate the capacity of the current operational version of the Climate Forecasting System (CFS) of the National Centers for Environmental Prediction (NCEP) to provide skillftil forecasts of cumulative precipitation at subseasonal time-scales over the Sahel region. For this we use the database of subseasonal-to-seasonal retrospective forecasts conducted at NCEP for the period from 1982 to 2004. Both measures of deterministic and probabilistic scores are used. Copyright 2006 by the American Geophysical Union.