锡林郭勒盟一次暴雪过程分析

Analysis on a Snowstorm Weather Process in Xilin Gol

2010年11月20日20时到21日08时锡林郭勒盟东北部出现了暴雪天气过程,这次暴雪是在两脊一槽的环流形势中西来斜压槽配合地面蒙古气旋产生的,属强冷空气类。极涡的维持使斜压槽加强,移动缓慢;在印缅槽维持的西南环流场中,700hPa西南槽为华北建立了水汽通道,暖湿的低空西南急流提供了较好的水汽和能量不稳定条件;高低空急流耦合产生了动力抬升作用,大、暴雪就发生在高空急流入口区右侧,低空急流左侧的耦合区。逆温层和高能舌的存在为暴雪的发生储备了潜在能量。

A snowstorm weather process appeared from twenty o＇clock on November 20th,2010 to eight o＇clock on November 21th,2010 in northeast of Xilin Gol league,which was generated by baroclinic trough coming from the West with the ground Mongolia cyclone in the background of two troughs and one ridge,and it was a strong cold air category.The maintenance of the polar vortex made the baroclinic trough strengthen and slow move.In the southwest circulation field which was maintained by India and Burma trough,the southwest trough of 700hPa established the water vapor channel to North China,the warm,moist and low-level southwest jet provided good moisture and energy instability conditions.The coupling effect of high and low level jet produced a dynamic lifting function.The snowstorm appeared on the right side of entrance area of upper-level jet and in the coupling area on left of low-level jet.The inversion layer and high-energy tongue reserved potential energy for the occurrence of the snowstorm.