利用24h降水实况资料和高空实况形势场资料、ECMWF模式形势场预报资料及ECMWF、JMA、T639模式降水预报资料,对2015年江西省汛期(4月上旬至7月上旬)区域性暴雨的时空分布特征进行分析,并对2015年江西省汛期区域性暴雨的影响系统和降水预报结果进行了短期主观检验,对比分析了ECMWF、JMA和T639等3种数值模式对江西省区域性暴雨系统预报的效果.结果表明:ECMWF模式对江西省汛期暴雨天气系统的调整和演变具有一定的预报能力,如对副热带高压和西南急流的预报;但随着预报时效增加,预报误差增大.ECMWF模式预报的48 h和72 h副热带高压强度较实况明显偏弱,预报的副热带高压西脊点位置偏东,随着季节转变预报的副热带高压强度明显偏弱,其中24h预报的准确率较高.ECMWF模式对高空槽的预报基本准确;ECMWF模式对切变线移动的总体预报效果较好,72 h预报的切变线移动偏慢;ECMWF模式对700 hPa西南急流强度的预报易偏弱,对850 hPa和925 hPa西南急流的预报易偏强;ECMWF模式预报的急流轴位置多数偏北;ECMWF模式对低层比湿的预报较实况偏强.随着预报时效临近,ECMWF、JMA和T639等3种数值模式对江西省汛期区域性暴雨的预报具有较强的调整能力;JMA模式预报的暴雨与实况最接近,表现出对雨带分布具有较强的预报性能,但对降水量级预报偏弱;ECMWF模式对降水强度的预报性能较好,预报的降水分布总体偏北;T639模式预报的主雨带范围较实况偏大,3个模式均存在对暴雨以上量级降水漏报的问题.%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.
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