新疆天山中部初秋罕见大暴雪成因分析

对新疆天山中部初秋2003年9月27—28日罕见大暴雪天气过程进行综合分析表明:天山中部初秋大暴雪发生在南亚高压双体型,伊朗副高东伸北挺,西太副高稳定,乌拉尔大槽不断南伸并缓慢东移的形势下;它是各种尺度系统及副热带与西风带系统共同作用的结果。大暴雪发生在低层偏东气流与中层西南气流和高层偏西气流交汇处;而低层东路水汽的输送对大暴雪的贡献极为重要。

A Snowstorm Origin Analysis in Early Autumn at Middle Part of Xinjiang Tianshan Mountains

This article analyzed thoroughly"2003.09.27-28" infrequent snowstorm process in the middle part of Tianshan Mountains in Xinjiang.The results indicated that the snowstorm took place under as follows circumstances: south Asia high have been pair-type,Iranian subtropical high extended eastward and northward,western Pacific subtropical high have been steady,Ural deep trough held up southward unceasingly and moved to east slowly.Further more the snowstorm was a result as mutual action that combined various scales systems and the systems of subtropical and westerly belt.The snowstorm happens to the overlapping region at the partial to east current of low-level,the partial to south current of middle-level and the partial to west current of high-level.It is very important that vapor transport of low-level from east.