Interpretation and Analysis of Heavy Rain Event in Sichuan by Ensemble Prediction Based on Standardized Anomaly Forecasting

Based on the definition of regional heavy rain in Sichuan,the regional heavy rain in Sichuan from 2012-2016 have been screened.In this paper,the specific humidity (q) and meridional wind (v) of 850hPa are selected,and a method known as Ensemble Anomaly Forecasting,which combines ensemble forecasts with climatology,is applied by using the data of NCEP reanalysis and ensemble prediction of EC model.The results show that the standardized anomaly (SA) of the specific humidity (q) and the southerly wind (v) at 850hPa are more applicable to the regional heavy rain in the eastern basin,and the precipitation area above 50mm generally occurs in the area with the maximum value of standardized anomaly of specific humidity (q) and meridional wind (v) at 850hPa.In the regional heavy rain of eastern basin,60% of the heavy rains in the rainstorm center,the probability of a standard deviation of 850hPa over the climatological average reached 80%,and the probability of exceeding 1.5 standard deviations reached more than 50%.