长江上游暴雨短期集合预报系统试验与检验

Simulation and Test of Short-Range Ensemble Prediction System for Heavy Rainfall in the Upper Reach of Changjiang River

基于PSU/NCAR的高分辨率MM5模式,采用多物理方案构建长江上游中尺度集合预报系统,于2004年8月16日—9月30日进行了预报试验。降水集合预报检验表明,在25mm以上级别的降水预报中,集合预报能改进单一模式的预报能力。对“9·3”暴雨过程的检验表明,降水集合预报平均对暴雨过程的开始、持续、结束时间均有预报指示意义,特别是大于50mm的降水概率分布区域和值的大小对预报大降水的范围有指导作用。

Based on the PSU/NACR Mesoscale Model version MM5, mesoscale ensemble prediction system in the upper reach of Changjiang River is constructed by using different physics schemes. Ensemble prediction experiments and verifications for precipitation are made during 16 August to 30 September of 2004. The results show that the ensemble prediction can increase prediction accuracy of precipitation over 25mm. The experiment results of a heavy rainfall case occurring on 3 September indicate that the ensemble precipitation prediction mean might give a good clue to the starting, duration, and ending of heavy rainfall process, especially precipitation probability distribution more-than-50mm. The rainfall prediction has better guidance for area of heavy rainfall.