Statistical Prediction Model for Summer Extreme Precipitation Events over Huaihe River Valley

The atmospheric circulation anomalies in winter and spring associated with the year-to-year increments of summer extreme precipitation event frequency over the Huaihe River valley (HRF) were analyzed during 1962-2005 to identify five key HRF predictors by using a year-to-year incremental approach. These indicators include the North Pacific Oscillation (NPO) in winter, the Antarctic Oscillation (AAO) in December, sea level pressure over the region of the south Indian Ocean and Bering Sea in March and April (MA), and the meridional wind shear between 850 hPa and 200 hPa over the Indo-Australian plate region in MA. A prediction model for year-to-year increments of HRF is established by using the multi-linear regression method. The predicted value of each year’s increment of HRF is added to the observed value within a particular year to yield the HRF forecast. Cross-validation testing shows that the prediction model has a high skill for HRF with a correlation coefficient of 0.67 during 1962-2005. Thus, this prediction model has a high potential for accurate HRF forecasting.