Abstract: 24-hour precipitation and weather patterns observations data,model products of weather patterns from ECMWF and precipitation from ECMWF,JMA and T639 were used to analyze the spatial-temporal distributions of 15 regional rainstorm events over Jiangxi province during the flood season (from early April to early July) in 2015.Short-range validation was carried on for the forecasting synoptic systems and precipitation to evaluate the forecasting skills of weather patterns by the ECMWF model and the precipitations by three other models.The results show that ECMWF has certain capacities to forecast the adjustment and evolution of weather patterns,e.g.subtropical high and Southwest Jet over Jiangxi province during the flood season,though the errors increase with a length of forecasting time.Although the accuracy of ECMWF 24-hour forecasts is relatively high,the 48-hour and 72-hour intensities of subtropical high from the ECMWF model are significantly weaker than those of observations.The ridge location of subtropical high predicted by the ECMWF model is located more eastward and the intensities of subtropical high appear weaker with seasonal change.The high-level troughs and shear lines are rather accurately forecasted by ECMWF,except for a little slower in the movement of 72-hour shear lines forecasting.ECMWF tends to predict weaker Southwest Jets at 700 hPa,stronger ones at 850 hPa and 925 hPa,and higher relative humidities at lower levels as well.Each of the three models has significant capacity to regulate the forecast for regional rainstorms over Jiangxi province.The forecast skill of JMA ranks the number one,showing the best skill for precipitation distribution forecast despite the values seem smaller.Although the locations are generally northward,the precipitation intensity from ECMWF is well predicted.The main precipitation belts from T639 are broader than observations.All three models have deficiencies of missing forecasts of precipitation from extreme heavier rainstorm events.

Key words: Numerical model, Synoptic validation, Regional rainstorm, Forecast error, Flood season