中文摘要：

利用常规观测资料、陕西地面加密观测资料和NCEP再分析资料对2006年6月2日00：00（协调世界时,下同）至3日12：00陕西中部初夏的一次区域突发性暴雨进行了数值模拟和综合分析。结果表明受500hPa冷涡底部短波槽、700hPa切变线和地面偏东风气流的共同作用造成这次突发区域性暴雨。模式结果与实况降水情况基本一致,24h降水模拟能够很好地体现暴雨过程的中心位置,暴雨区域的主要范围和暴雨形势的走向。垂直运动场和降水区对应较好。通过对位涡的分析可得到,此次暴雨过程中有一股很强的干冷空气从对流层顶向下传播,这种强干侵入的形式有利于强降水的生成。广义位温和对流涡度矢量异常的分布和垂直变化很好地反映了陕西这次暴雨过程的落区及其演变,并且对本次暴雨的预报有较好的预报指示意义。

英文摘要：

The distribution of annual precipitation, which is affected by mountainous terrain, decreases from south to north in Shaanxi Province. Annual precipitation is 400-600 mm in northern Shaanxi and approximately 500-700 mm in Guanzhong. In the south, however, annual precipitation is 700-900 mm. In the Micang, Daba, and Qinling mountains of southern Shaanxi, as well as in the western mountains areas, annual precipitation reaches 900-1250 mm. In addition, this precipitation exhibits significant seasonal variation. Precipitation is significantly higher in summer than in other seasons, accounting for 39% to 64% of the entire annual precipitation, and is concentrated in northern Shaanxi. In early summer before late June to early July, heavy rainfall gathers in southern Shaanxi. Due to the sudden increase in local precipitation, rainfall prediction is difficult. The case of a heavy rainfall event occurring in southern Shaanxi and Guangdong during 2-3 Jun 2006 is examined. Data was acquired through a variety sources including observation analysis, numerical simulation, and diagnosis analysis. The effects of a short-wave trough at the bottom of a cold eddy at 500 hPa, a shear line at 700 hPa, and a surface easterly are examined. The main factor triggering this storm was a sudden increase in the southeastward jet at 925 hPa and 850 hPa in the low troposphere. The process of this storm was simulated by the Weather Research and Forecasting （WRF） model. The results are essentially consistent with the actual precipitation values. The heavy rain area, the center of maximum precipitation, and vertical velocity are consistent with the observations. Moreover, present value potential vorticity analysis indicates that a very strong cold dry air mass propagating from the top of troposphere in this heavy rainfall process promoted the formation of severe precipitation. The change in vertical velocity and the general potential temperature and distribution of the abnormal convective vorticity vector （CVV）, which were all obtained th