一次华南暴雨的可预报性分析

Analysis of the predictability of a rainstorm in South China

利用WRFV3.2.1数值模式,以2009年7月2-3日华南暴雨为例,考察随机添加的初始场误差在此次暴雨中的演变过程。结果表明:添加在初始场的误差随着积分过程延长对模拟结果的改变逐渐增大,且湿过程误差造成的模拟结果改变更大;从空间上来说,模式对高层温度的预报能力较差,对低层风场的预报能力较好;暴雨的可预报性与水汽场的精确度有关,水汽初始场越准确,暴雨的模式可预报性就越长,初始风场对暴雨模拟结果主要体现在经向风场的影响上,经向风场越准确,暴雨的可预报性就越好。

In order to study the evolution of error growth in rainstorm over South China, a case of heavy rainfall from 2-3 July 2009 was studied by WRFV3.2.1. The results indicated that： the error of the initial field increased with the extension of the integral process, and the simulation results change gradually, furthermore, changes caused by the error of wet process was bigger; the prediction ability of model was poor to high-level temperature, but it was suitable for forecasting the low-level wind field. The predictability of South China rainstorm was related to the accuracy of water vapor and meridional wind, the more accurate the initial moisture and meridional wind field were, the better the predictability of rainstorm would be.