石河子地区一次强对流天气综合分析

针对2008年主汛期期间7月25—26日在新疆石河子地区出现的冰雹、雷暴、短时强降水等强对流天气过程，对大尺度的天气形势、卫星云图和新一代天气雷达产品进行分析，剖析了石河子地区出现强对流天气的环流背景以及雷达产品的特征。结果表明：此次过程中高空有明显的低槽不断向该地区分裂干冷空气，并与槽前西南气流和中低层的辐合系统相配合，使得对流有效位能不断积累，不稳定指数不断增大，为这次强对流天气过程提供了有力的动力、热力条件。局地出现的冰雹、雷暴、短时强降水与大于50dBz的回波强度、9km以上的云顶高度和45—50kg／m^2的VIL回波特征，在雷达图上均有较好的对应，且发生地与回波的移动方向相一致。

Characteristic Analysis of a Strong Convective Weather in Shihezi Area in July 25-26 2008

The strong convective weather of hail, thunderstorms and heavy precipitation in a short time happened in Shihezi area in July 25-26, 2008 during the main flood season. We analyzed the large-scale weather patterns, satellite image and new generation weather radar products , and took apart the circulation background of strong convective weather and characteristics of radar products in Shihezi area. The results show that: the significant trough in middle-high altitude splits dry cold air to Shihezi region continuously, and cooperates with the south-west air current ahead of trough and the middle-low level convergence system, making CAPE continue to accumulate, and increasing instability index all the time, provide dynamic and thermodynamical conditions for this strong convective weather. Local hail, thunderstorm and heavy rainfall in a short-term are coincide with the echo intensity of more than 50dBZ, the height of cloud top above 9km and VIL echo characteristics of 45-50kg/m2 at the radar chart. And the occurrence place is consistent with the moving direction of echo.