A Seamless Approach of Improving Climate Projection for US Great Plains

CMIP5 climate models and projections show large uncertainty over the US Southern Great Plains (SGP), making them inadequate for regional drought mitigation and adaptation planning. We have carefully evaluated and corrected the biases of CMIP5 models in representing summer rainfall and droughts over the SGP using the observed statistical relationship between the anomalous large scale circulation and land surface conditions in spring and summer rainfall anomalies over this region. The creditability of the statistical relationships or model has been tested through seasonal hindcasts and forecasts. The latter has been used by the Texas Water Development Board (TWDB) to brief the state drought preparedness council and stake holder. Because the underlying physical processes that control summer rainfall is unlikely to change between the current and future climate, the prediction skill established at seasonal scale can provide not only a scientific basis, but also public confidence, for applying this statistical model to bias-correction of future climate projections of the summer rainfall over the US SGP. This proposed paper for special issue will show the methodology, results and prediction skills of the summer drought early warning indicator.