统计1995—2010年东北方向登陆影响云南省的孟加拉湾风暴,根据降水强度及降水落区,将10个个例分为区域性降水、全省性降水来加以研究.对孟加拉湾区域(80°~100°E)云顶亮温资料(TBB)进行纬向平均,通过分析云顶亮温的纬向平均时间演变图,发现TBB低值中心位置、强度与云南省降水有一定对应关系,对于区域性降水,当-30℃TBB低值中心在20°~22°N附近,滇西及滇西北降水为大雨局部暴雨;对于全省性降水,当-40℃TBB低值中心位于14°~18°N附近,-40℃线的南北纬向宽度大于4°,另外20°~30°N区域的纬向TBB平均值低于-10℃,云南省降水以大雨局部暴雨为主.另外对于全省性降水,在降水产生前12~24 h的纬向TBB平均时间演变图中,若低值中心北侧的-30℃线的纬度为X°N,云南省的强降水区域位于(X+5)°N以南地区.
To analyze the TBB characteristic of storms over the bay of Bengal with impact on Yunnan province,storms over the bay of Bengal of Northeast path affecting Yunnan province form 1995—2010 has been counted at first,then dividing ten cases into regional and provincial types according to the precipitation intensity and precipitation areas. Finally,we've calculated the latitude inalaverage of satellite data about the bay of Bengal area( 80°—100°E) and analyzed its time evolution characteristics. The results show that there exists some relationship between the low center positionintensity and Yunnan precipitation. For the regional precipitation type,the heavy precipitation appeared in Western and northwest of Yunnan when the low center is located around 20°—22°N. For the provincial precipitation type,when the-40 ℃ low center is around 14°—18°N and the north and south latitude width of-40 ℃ more the four latitude and the average value of TBB lower than- 10 ℃ around20—30 degrees north latitude,there will be heavy rain and local storm in Yunnan Province. If the low center line north of the latitude of-30 ℃ is X degree of TBB average time evolution 12—24 hours before the precipitation produced,the heavy rainfall areas are likely to be located in south of( X+5) latitude regions for provincial precipitation.