2009年8月吉林省东南部霜冻天气分析

目的]分析2009年8月吉林省东南部霜冻天气。方法]利用NECP再分析资料和常规观测等资料,应用天气学分析和诊断方法,从环流形势、天气要素特征等方面对2009年8月吉林省东南部霜冻天气的产生进行了分析。结果]这是一次具有寒潮爆发性质的强冷空气影响过程;前期高空形势稳定,吉林省高温少雨,后期极涡大槽加深发展,强冷空气南下,在大槽冷锋东移之后,冷空气在该省爆发;吉林省东南部地区霜冻天气产生条件是东亚大槽和强冷锋的过境、高空处在西北气流的控制之下,该省中东部850 hPa温度)≤4℃,冷高压中心强度达1 020 hPa,且位置恰处该省中东部地区,冷空气的控制时间≥36 h、48 h内降水<10 mm。结论]这次过程中产生的天气条件和要素条件对今后夏季霜冻天气预报有重要意义。

Analysis on Frost Weather in Southeast Jilin Province in August of 2009

Objective] The research aimed to analyze frost weather in southeast Jilin Province in August of 2009.Method] Based on NECP reanalysis data and routine observation data,by using synoptic analysis and diagnosis methods,generation of the frost weather in southeast Jilin in August of 2009 was analyzed from circulation situation,weather factor characteristics and so on.Result] It was a strong cold air influence process with cold wave outbreak property.In prior period,upper situation was stable.It was high-temperature and rainless in Jilin.In later period,polar vortex and big trough deepened and developed,and strong cold air went south.After big trough and cold front moved eastward,cold air outbroke in the province.Generation condition of the frost weather in southeast Jilin was that East Asian big trough and strong cold front transited,and high altitude of Jilin was controlled by northwest airflow.850 hPa temperature ≤4 ℃ in central east Jilin.Center intensity of the cold high reached 1 020 hPa,and it was just in central east Jilin.When control time of the cold air ≥36 h,rainfall <10 mm in 48 h.Conclusion] Weather and factor conditions in the process had important significance for future frost weather forecast in summer.