辽宁地区“8.16”特大暴雨过程数值预报产品检验

Validation on numerical forecast products during the “8.16” severe torrential rain in Liaoning province

利用地面气象站和探空观测资料,对2013年8月16日辽宁地区特大暴雨过程数值模式预报的产品进行检验和对比分析,主要包括降水、500 h Pa位势高度场和副热带高压指数等。结果表明:一般性降水预报准确率T639模式整体优于EC模式,暴雨预报平均准确率EC模式略高于T639模式,T639模式和EC模式降水预报正负距平出现位置近似。多个数值模式对清原站主要降水时段(8月16日11—23时)的降水预报明显偏弱,WRF模式预报的全省3 h最大降水量远大于实况,T639模式和EC模式预报的降水量级均明显小于实况。EC模式和多模式集成72 h内降水落区与强降水中心位置的预报相对较稳定,过去15 d的滑动平均检验结果对降水预报具有一定的指示意义,72 h内EC模式的特征线预报一致性明显高于T639模式,对于辽宁省大部地区及上游高空槽附近EC模式降水预报的离散度小于T639模式。

Based on observational data from surface meteorological stations and radiosonde data, the forecast prod- ucts, such as precipitation, geopotential height field at 500 hPa, subtropical high index, from different numerical models for the severe torrential rain event on August 16,2013 were validated and comparatively analyzed. The re- suits show that general precipitation forecast accuracy of the the T639 model is better than that of the the EC mod- el, and the mean forecast accuracy of rainstorm from the EC model is slightly better than that from the T639 mod- el. The spatial distribution pattern of positive and negative precipitation anomaly of the T639 is similar to that of the EC. The precipitation predicted by different numerical models is all significantly smaller than observations dur- ing the main precipitation period （ 11：00-23：00 on August 16） at Qingyuan station,and the 3-h maximum precipi- tation predicted by the WRF model is much larger than the real precipitation. The precipitation grades predicted by the T639 and the EC are both smaller than the real grades. The 72-h precipitation area and the center position of strong precipitation predicted by the EC and an ensemble model are relatively stable. The 15-d moving averaged validating results have some referential meaning to the precipitation forecast. The consistency of 72-h characteristics line predicted by the EC is better than that predicted by the T639, and the dispersion of precipitation predicted by the EC over the most regions of Liaoning province as well as upper trough in the upstream region is smaller than that predicted by the T639.