2010年5月6日福建省南部地区暴雨预报偏差原因分析

Causal analysis of the forecast deviation of the rainstorm in southern Fujian on May 6,2010

利用气象常规、非常规观测资料，对2010年5月6日福建南部一次暴雨预报失误进行分析。结果表明：预报失误的主要原因是对在前倾槽形势下，低空急流和切变迅速南压估计不足。低空急流和切变的迅速南压，在福建南部地区形成强的低空辐合，有利于水汽和能量的积累；200hPa强辐散和强烈深厚的上升运动为大暴雨的产生提供了动力条件。

Using the conventional and non-conventional observation data, the forecast deviation of the rainstorm in southern Fujian on May 6,2010.is investigated.Results indicate that： The main cause of forecast deviation is that we underestimated the rapid southward of low-level jet and shear under forward-tilting trough circumstances. Low-level jet and shear moved rapidly to form strong low-level convergence in southern Fujian,thus was beneficial to accumulate water vapor and energy.At the meantime,the intense divergence and strong ascending motion at 200hPa level also provided the dynamic factor for the rainstorm.