松嫩平原西部局地暴雨天气成因分析

利用常规气象观测、卫星、雷达和NCEP1°×1°再分析等资料，分析2013年6月27~28日齐齐哈尔市稳定性中雨和龙江县对流性暴雨天气成因，结果表明：龙江短时强降雨出现在850hPa切变线同500hPa槽线或850hPa干线位置近于重合时，层结不稳定，上升运动强；齐齐哈尔降雨发生在低层切变线附近，层结趋于稳定，上升运动弱。地形迎风坡作用有利于龙江降雨强于齐齐哈尔。 单站风、相对湿度和垂直速度时空变化差异以及对流有效位能、大气可降水量和SI指数等物理量可以反映两地上升运动、水汽、层结不稳定条件差异。较好的水汽和大气层结不稳定条件只是对流性短时强降水的必要条件。中尺度对流云团和小尺度对流云回波产生龙江短时强降雨，齐齐哈尔稳定性较大降雨由层状云产生。

Analysis on the Reasons Causing the Stable Rainfall and the Convective Rainstorm in Two Adjacent Stations in the West of the Songnen Plain

Using the convetional meterological data, satellite images, Dopplor weather radar data and the NCEP 1°×1°reanalysis data, the reasons which cause the convective rain storm in Longjiang County and the stable rainfall in Qiqihar city in the West of the Songnen Plain from 27th June to 28th June in 2013 is analyzed. The results show that Longjiang County convective rain appears near the 850hPa shear line coincide with the 500hPa trough or the 850hPa dew-point front. While the rainfall is happening in Qiqihar city, the atmospheric stratification is stable. The terrain effect is conducive to the stronger rainfall in Longjiang County .The differences of the Cyclonic change of wind , the relative humidity , the rate of increase in spatial-time and the convective available potential energy and the atmospheric precipitation , K and KY and SI index reflect the different condition of ascending motion, water vapor, the atmosphere instability between Longjiang and QiqiHar. The convective and short-term strong rainfall was produced by a mesoscale convective cloud cluster and the mixed cloud precipitation Radar echo, and the stable rainfall was produced by stratiform cloud .