[ Objective] The research aimed to analyze frost weather in southeast Jilin Province in August of 2009. [ Methed] Based on NECP rean- alysis data and routine observation data, by using analytic and diagnostic methods ...[ Objective] The research aimed to analyze frost weather in southeast Jilin Province in August of 2009. [ Methed] Based on NECP rean- alysis data and routine observation data, by using analytic and diagnostic methods of the synoptics, frost weather in southeast Jilin Province in Au- gust 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, high-altitude situation was stable, and it was high-temperature and rainless in Jilin. In later peri- od, polar vortex and big trough deepened and developed, and strong cold air went south. After big trough and cold front moved eastward, cold air erupted in the province. Generation condition of the frost weather in southeast Jilin Province was that East Asian big trough and strong cold front transited, and high altitude of Jilin Province was controlled by northwest airflow. 850 hPa temperature ≤4 ℃ in central east Jilin Province. Center intensity of the cold high reached 1 020 hPa, and it was just in central east Jilin Province. Control time of the cold air ≥36 h, and rainfall 〈10 mm in 48 h. [ Cendusion] Weather and factor conditions in the process had important significance for future frost weather forecast in summer.展开更多
文摘[ Objective] The research aimed to analyze frost weather in southeast Jilin Province in August of 2009. [ Methed] Based on NECP rean- alysis data and routine observation data, by using analytic and diagnostic methods of the synoptics, frost weather in southeast Jilin Province in Au- gust 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, high-altitude situation was stable, and it was high-temperature and rainless in Jilin. In later peri- od, polar vortex and big trough deepened and developed, and strong cold air went south. After big trough and cold front moved eastward, cold air erupted in the province. Generation condition of the frost weather in southeast Jilin Province was that East Asian big trough and strong cold front transited, and high altitude of Jilin Province was controlled by northwest airflow. 850 hPa temperature ≤4 ℃ in central east Jilin Province. Center intensity of the cold high reached 1 020 hPa, and it was just in central east Jilin Province. Control time of the cold air ≥36 h, and rainfall 〈10 mm in 48 h. [ Cendusion] Weather and factor conditions in the process had important significance for future frost weather forecast in summer.
