Weather Process Analysis of A Heavy Snow to Blizzard in Benxi Region

ZHANG Hai-jun;WANG Huan-yi;Benxi County Meteorological Administration in Liaoning Province;Benxi Meteorological Administration;

weather process of a heavy snow;;northeast cold vortex;;north China trough;;low altitude jet flow;;precipitation phase;;Benxi Liaoning

The article analyzed the big to the blizzard process of Benxi area during March 3rd to 4th in 2014 by the ground in the process of encryption automatic weather station precipitation data andconventional sounding data and T639,Japan,Europe numerical product output data.The analysis of the circulation background and physical quantity diagnosis revealled the large scale circulation background;high and low air jet and the evolution of the ground cyclone influence on the process of big to blizzard.The results showed that the process was caused by large scale circulation background,the stable development of northeast cold eddyandrural mountains ridge contribute to the cold air southward continuously and the low system establishment and development in western Liaoning,which provided strong circulation background for the heavy snow of Benxi area.The precipitation of Benxi in marchmainly included snow,sleet and rain,we could forecast the precipitation phase by the temperature of 850 h Pa and 925 h Pa,ground temperature and the 0 ℃ layer height;Under the influence of low level jet,southwest of warm moist air rised along the low-level jet and generatesunstable atmospheric layer of warm,moist upper part and dry,cold lower part,low level jet played an important role to the big to blizzard process of produce and maintainas lower energy and water vapor concentration of conveyor belt;The Shear line,the height and low of air jet and ground inverted provided powerful dynamic conditions for the heavy snow.