湖北西北部一次局地暴雨的发生机理

Analysis on A Local Heavy Rain in Northwest Hubei Province

2009年7月8～13日湖北省西北部出现了一次罕见的盛夏阴雨天气过程中局地暴雨天气,分析探讨了该过程的环流形势及动力、热力和水汽等对这次强降水的贡献。结果表明,巴尔克斯湖冷涡带来的冷空气是局地暴雨的触发机制,贝加尔湖低压为东亚环流调整提供了外来动力,暴雨发生时散度场在高空辐散具有强烈"抽吸作用",孟加拉湾暖湿气流和南海暖湿空气是暴雨的水汽源,暴雨落区出现在能量锋区前部、高能舌顶端轴线偏向冷空气一侧,Q矢量散度、水汽螺旋度负值区对于局地暴雨的短期预报有重要的指示作用。

A rare rainy weather appeared in northwest of Hubei Province during July 8th-13th,2009. The process of circulation was analyzed,the contribution of power,heat and water vapor on the intensity of precipitation were discussed. The results showed that：Balkis Lake brings cold air cold vortex is the trigger mechanism of storm,Lake Baikal,the adjustment of low pressure circulation in East Asia a foreign power,heavy rain occurs in the upper divergence divergence with a strong ＂suction effect＂ Bay of Bengal and South China Sea warm air warm and moist air is heavy rain the water vapor source,heavy rain area in front of energy front,cold air,high-energy side of the tongue to the top axis deviation,Q vector divergence,water vapor helicity negative area for the Council short-term forecasting of storm has an important role in instruction.