青藏高原东北部近10年大到暴雪天气过程分析

A Case Study of Heavy Snow to Blizzard in the Northeast of Qinghai-Tibet Plateau in Recent Ten Years

为了研究西宁市大到暴雪的发生机制,总结短期预报思路,建立短期预报指标,利用Micaps常规天气和物理量场等资料,采用天气学诊断方法,分析近10年西宁市出现的5次大到暴雪天气过程。分析表明,环流形势可以分为北脊南槽型、西高东低型、阶梯槽型、贝湖低槽型。西宁市大到暴雪天气的发生与地面冷高压、500 h Pa高空槽、切变线、孟湾风暴、西南气流有关。对于西宁地区大到暴雪预报指标,应从有无冷空气过境、是否有西风带短波槽及高原南支槽东移影响、是否有西南气流、700 h Pa冷温槽0℃是否南压至西宁地区等方面确定。

In order to study the mechanism of heavy snow to blizzard in Xining City,summarized the short-term forecast ideas and establish short-term forecast indicators ,this paper used Mieaps conventional data,physical field and the method of weather diagnosis to analyze 5 times heavy snow to blizzard weather process in Xining City in recent 10 years.The results showed that the circulation situation could be divided into the north ridge south trough type,Wushan ridge type,stepped trough type and Beihu low trough type.The occurrence of heavy snow to blizzard in Xining City was relation to the ground cold high pressure,500 hPa upper trough,share line,Bay of Bengal storm and southweat air.The forecast indicators about heavy snow to blizzard of Xining area, should be determined by whether cold air transit, whether the westerlies short wave trough and the plateau south trough eastward impact,whether there was southwest airflow and whether 0℃ of 700 hPa cold temperature trough was moving southward to Xining area.