Shortcasting Activities at the Climate Hazard Group

The Climate Hazard Group specializes in statistical short-lag forecasts of precipitation and precipitation-related variables, especially in areas with a high risk of famine. Note that most crops have about a 120 growing cycle, and generally require most water at mid-season. A ‘shortcast’ made near the onset of the season can be fairly accurate, since the need to project far into the future is minimized. Since the affected crops will not be harvested until after the season, this approach can lead to effective predictions of drought with lead times of greater than half a year

Recent CHG activities have focused on three areas of concern: Ethiopia, Southern Africa and Central America. Our work in Ethiopia1 showed that early season rainfall is a predictor of overall crop yields at a national level. This in turn allowed us to make accurate estimates of food shortages far in advance. In Southern Africa our research suggests an opposite relationship, with early season positive anomalies often being associated with below average late season rains2. Our work has also suggested that upper-level winds can play a strong role in influencing sub-tropical precipitation in Africa3, 4, and that these fields and sea-surface temperatures can be used to predict
Southern African crop production5.

The CHG also works with climate forecasting groups, such as the International Research Institute for Climate Prediction (IRI), and NOAA’s Climate Prediction Center (CPC) to improve hazard early warning by interpreting probabilistic forecasts6 and developing methods to merge monitoring and forecast information7.