CHG - Forecasts

The Climate Hazards Group develops forecasts in conjuction with the FEWS Network and affiliates around the world. These forecasts are made available for easy distrubtion among local decision makers to mitigate or prevent food insecurity in vulnerable and developing regions.

GEFS Skill

Skill with respect to CHIRPS (images coming soon).


The Global Ensemble Forecast System (GEFS), previously known as the GFS Global ENSemble (GENS), is a weather forecast model made up of 21 separate forecasts, or ensemble members. The National Centers for Environmental Prediction (NCEP) started the GEFS to address the nature of uncertainty in weather observations, which is used to initialize weather forecast models. The proverbial butterfly flapping her wings can have a cascading effect leading to wind gusts thousands of miles away. This extreme example illustrates that tiny, unnoticeable differences between reality and what is actually measured can, over time, lead to noticeable differences between what a weather model forecast predicts and reality itself. The GEFS attempts to quantify the amount of uncertainty in a forecast by generating an ensemble of multiple forecasts, each minutely different, or perturbed, from the original observations.