J4 ›› 2010, Vol. 28 ›› Issue (4): 438-442.

• 论文 • 上一篇    下一篇

天山北坡中部一次罕见特大暴雪天气成因

赵俊荣郭金强   

  1. (新疆石河子市气象局,新疆石河子832000)
  • 收稿日期:2010-04-08 修回日期:2010-08-24 出版日期:2010-12-31 发布日期:2010-12-31

Diagnosis of a Torrential Snowfall Weather Occurred on the North Slope of Tian Mountain in February of 2010

ZHAO Junrong,GUO Jinqiang   

  1. (Shihezi Meteorological Bureau,Shihezi 832000,China)
  • Received:2010-04-08 Revised:2010-08-24 Online:2010-12-31 Published:2010-12-31

摘要:

利用我国数值预报产品T6390场预报资料和新疆天山北坡中部地区的地面降雪量资料,分析新疆天山北坡中部地区2010年2月23日发生的罕见特大暴雪天气的特征及这次过程形成的原因。结果表明:这场罕见特大暴雪天气具有降雪强度强、范围广、积雪深度异常偏厚、灾情严重等特点,属60 a不遇。乌拉尔山长脊、西伯利亚冷涡东移为罕见特大暴雪天气的发生提供了大尺度环流背景,冷涡外围强锋区中分裂出的中尺度短波、西南急流、700 hPa中尺度辐合带、850 hPa“人”型切变场、中高压、中低压以及地面冷锋是特大暴雪的直接影响系统;高低空形势场、急流和锋区以及中尺度的动力、水汽因素的有利配合为特大暴雪的发生提供了必要条件。特大暴雪发生在高空锋区短波槽前的冷暖平流交汇区、700 hPa中尺度辐合带、850 hPa“人”型切变场、西南急流、地面冷锋、中低压后部和中高压前部、强的能量锋区、高湿区以及水汽通量辐合区的重合区域内。特大暴雪发生过程中,天山北坡中部上空维持一个由低层到高层强盛的动力性纬向垂直环流圈,为冷暖气流共同作用提供了动力条件;正、负涡度中心的配置,有助于天山北坡中部上空的低值系统和锋区的加强。高空急流加强了特大暴雪天气的上升运动;强盛的低空西南暖湿急流将里咸海地区的高温高湿不稳定气流输送到天山
北坡中部上空,为特大暴雪天气提供了热力、水汽和不稳定能量的条件。

关键词: 天山北坡中部, 罕见特大暴雪, T639产品, 成因分析

Abstract:

Based on the mathematical forecast product“T639”and snowfall data in the middle part of the north slope of Tian Mountain,this paper analyzed the synoptic character and causes of the torrential snowfall weather ocurred there on February 23 of 2010.Results show that Ural ridge and Siberian cold vortex moving to eastward provided large scale circumfluent background for this snowfall weather,and the mesoscale short wave,southwest jet stream,700 hPa mesoscale convergence belt,850 hPa shear line,middle-high pressure,middle-low pressure and ground cold front were direct influence systems of this snowfall weather.The high-low level situation field,jet stream and front regions,and the favorable cooperation of middle scale momentum and water vapor,these all provided necessary conditions for this torrential snowfall weather.The high-level jet stream increased vertical movement,the strong low-level southwest warm and humid jet stream transported instable air flow with high temperature and humidity from the Caspian Sea and Black Sea to the middle level of Tian Mountain north slope,which provided heat,water vapor and unstable energy conditions for this orrential snowfall weather.

Key words: the north slope of middle Tian Mountain, torrential snowfall, product of“T639”, diagnosis

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