Diagnosis Analysis of a Heavy Snowfall Weather Process in Central and Eastern of Yunnan Province
A heavy cooling and snowfall weather in central and eastern Yunnan were occured from February 19 to 23,2022,in which Qujing had moderate to heavy snow,with local heavy snow or blizzard.In the paper,this heavy snow weather process was diagnosed and analyzed based on conventional observation data,physical quantity field,satellite cloud image and other data.The results showed that the south branch trough and the Kunming quasi-stationary Front/cold front were the main systems that caused the snowfall.The strengthening of southwest air flow,the increase of water vapor flux,the convergence of water vapor at the lower level and the divergence of water vapor at the upper level have provided better water vapor conditions for this snowfall process.And strong ascending motion provided necessary dynamic disturbance for the snowfall.The isotherm of-4℃at 700 hPa and the temperature line of ground temperature less than 0℃correspond to the location of the snow line.The satellite cloud image could clearly reflected the movement,convergence and development of the south branch trough and Kunming quasi-stationary front/cold font.The importance of continuously replenishing and strengthening cold air in the snowfall process were further confirmed based on the radar map.The analysis was carried out from various dimensions such as weather system,physical quantity field,satellite cloud image,radar echo,and obtained the index of snowfall weather in central and eastern Yunnan,which plays a clear indicating role in the future snowfall weather forecast.
heavy snowfallsouth branch troughKunming quasi-stationary frontsatellite cloud imagesdoppler radar
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NSTL
万方数据
