安徽一次暴雨过程的数值模拟与诊断分析

Numerical Simulation and Diagnostic Analysis of a Rainstorm Process in Anhui Province

利用1°×1°的GFS分析场数据和中尺度数值模式WRF，对2014年5月31日～6月1日发生在安徽阜阳的一次暴雨天气过程进行数值模拟和诊断分析。结果表明，WRF模式能够近似地模拟此次降雨过程；高低空急流耦合是此次暴雨过程发生和维持的主要影响机制；暴雨中心上空垂直螺旋度呈现高层负、低层正的分布，这也是触发暴雨的重要机制；降水开始前，大气呈现上湿下干的湿度分布，这种大气层结很不稳定，易导致降雨的发生。

Based on the 1°×1°analysis field data from GFS （Global Forecasting System）,with a mesoscale numerical model WRF （Weather Research and Forecasting model） ,a torrential rain occurred in Anhui Province from 31 May to 1 June ,2014 was simulated and diagnostically ana-lyzed.The results showed that WRF model has a good forecasting ability in a rainfall process;the coupling of the low-level and upper-level jet was the main dynamical mechanism of the out-breaking of this torrential rain process;the vertical helicity at the upper levels was negative while at the lower levels,it was positive; the atmosphere humidity at the upper levels was damp while at the lower levels it was dry before precipitation.