2007年5月8日新疆大降水过程分析

Analysis of Heavy Rain on May 8th 2007 in Xinjiang

利用常规天气资料、T213资料及FY2-C卫星云图分析了2007年5月8—9日新疆强天气过程中大降水的成因。分析得出:在春季强天气典型环流背景下,500hPa两支锋区在北疆西部汇合,西南气流在此加强,增强了水汽的输送;低空700～850hPa偏东气流是本次过程水汽输送的又一通道,其建立与大降水出现的时间同步,增强了辐合上升运动;地面锋面及鞍形场中气流辐合区的位置与降水落区较为吻合;中低层强烈的垂直上升运动及水汽的辐合对大降水起到了重要作用。

Using the routine weather data and the data of the T213L60 Numerical Model and also the nephogram of FY2-C to analyze the causes of heavy rain on May 8th to 9th 2007 in Xinjiang. We found that： under the typical circulation background of severe weather in spring, the combined action of two frontal zone in 500hPa in northwest Xinjiang increased the southwesterly flow and the transfer of water vapor. The easterly jet in 700 hPa and 850 hPa was another channel of the transfer of water vapor, it＇s establishment was at the same time with the heavy rain＇s occurence, moreover,it strengthened the convergence of upward flow. The frontal surface and the convergence zone in col pressrue field were keeping in with the precipitation area. The strongly up votical motion in middle and low layer and the convergence of water vapor had important effect on the heavy rain.