Experimental high-resolution subseasonal-scale forecasts
*Please note that new maps are typically available by 9 am GMT each Friday; however, if the latest forecasts from all models are not available, the maps will also be updated on Saturday and Sunday at 9 am GMT.
The maps below show high-resolution (5km X 5km) climate forecasts over the next 30 days for The Permanent Inter-State Committee for
Drought Control in the Sahel/Comité permanent Inter-Etats de Lutte contre la Sécheresse dans le Sahel (CILSS)-monitored countries in West Africa. These maps are generated by performing a quantile mapping-based bias-correction and downscaling of the forecasts from the North American Multimodel Ensemble (NMME) SubX project (Pegion et al., 2019), which provides climate forecasts based on multiple climate models. We are currently using climate forecasts from 5 of those models. The bias-correction and downscaling process involves two key steps: (1) downscaling of the SubX forecasts from a spatial resolution of about 100 X 100km to 5km X 5km and (2) bias-correction of downscaled forecasts at a daily scale using downscaled hindcast and observation climatologies of 7-day windows centered on the target day sampled from 1999-2016.
The maps show a multimodel forecast of (1) Consecutive dry days (longest spell of days with precipitation below 1mm) and anomaly, (2) total rainfall over the next 30 days, and (3) number of rainy days in weeks 1 to 4 that receive rainfall more than 0, 5, 10, 25, and 50mm. Multimodel forecast, in this case, is simply the median of the ensemble forecast of the above variables. In the near future, we plan to provide similar maps using temperature forecasts.
These are experimental forecasts generated by the support of NASA-SERVIR Applied Sciences Team grant 80NSSC20K0163.
Consecutive Dry Days
Current Month Skill
Total Rainfall in mm
Number of Rainy Days:
Absolute Anomalies - 30 days
Absolute Anomalies - Week 1
Absolute Anomalies - Week 2
Absolute Anomalies - Week 3
Absolute Anomalies - Week 4
Percent of Normal - 30 days
Mean Tmax in deg C
Mean Tmin in deg C