Between weather prediction (forecast at lead times from 0 to 14 days) and seasonal forecasting (forecast at lead times from month 3 and beyond) there is the yet unexplored domain of subseasonal prediction. Here we first show that during the monsoon season forecast of anomalies of cumulative precipitation over the Sahel area with the operational Climate Forecasting system is skillful at lead times between 10 and 35 days. We also show that the monsoon onset is a forecast challenge for the current operational CFS. During the 2006 and 2007 West African Monsoon seasons we conducted an experimental real time forecast posted daily on the web. We review the 2006 and 2007 monsoon seasons over the Sahel and describe the ability of the operational CFS to predict in real time the observed deficits and surpluses of cumulative precipitation. We finally discuss possible ways for improving the forecast skill by examining the impact of horizontal model resolution and initial conditions to precipitation over the Sahel. For this we use a series of experimental multi-resolution hindcasts at T62, T126 and T254, performed under NOAA's Climate Test Bed.