Journal of Arid Meteorology ›› 2022, Vol. 40 ›› Issue (3): 500-506.DOI: 10.11755/j.issn.1006-7639(2022)-03-0500

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Causes of a backflow snowstorm in southeastern Inner Mongolia under the background of cold pad and its radar echoes characteristics

ZHANG Guilian1(), LIU Lanbo2, MENG Xuefeng1, ZHANG Lu1, LI Linhui3   

  1. 1. Inner Mongolia Autonomous Region Meteorological Observatory, Huhhot 010051, China
    2. Baotou Meteorological Bureau of Inner Mongolia Autonomous Region, Baotou 014000, Inner Mongolia, China
    3. Inner Mongolia Autonomous Region Meteorological Bureau, Huhhot 010051, China
  • Received:2021-04-12 Revised:2021-10-15 Online:2022-06-30 Published:2022-06-28


张桂莲1(), 刘澜波2, 孟雪峰1, 张璐1, 李林惠3   

  1. 1.内蒙古自治区气象台,内蒙古 呼和浩特 010051
    2.内蒙古包头市气象局,内蒙古 包头 014000
    3.内蒙古自治区气象局,内蒙古 呼和浩特 010051
  • 作者简介:张桂莲(1966—),女,内蒙古呼和浩特人,正研级高级工程师,主要从事各种灾害性天气预报研究.E-mail:
  • 基金资助:


Based on meteorological observation data, Doppler radar (CINRAD/CA) observation data, global topography data (1°×1°) and NCEP FNL 6-hour reanalysis data (1°×1°), the blizzard weather in spring in southeastern Inner Mongolia on 20 March 2019 was analyzed. The results show that the process was a typical backflow heavy snowstorm weather, the southwesterly warm and humid air at 700 hPa climbed along the low-level cold pad to produce frontogenesis, which was the main cause of this backflow blizzard. Obvious vertical wind shear and temperature differences generated because of the northeasterly jet at 925 hPa and southwesterly jet at 700 hPa, resulting in strong dynamic frontogenesis, and the dynamic frontogenesis mechanism played a significant role. The convergence of divergence at low-level was conducive to development of vertical upward movement. The southerly and easterly at 850 hPa transported water vapor to the southeast of Inner Mongolia. There was a strong inversion stratification between 850 hPa and 700 hPa, where the cold and warm air met violently. The north-south topography of the Greater Khingan Mountains had a blocking effect on the northeasterly ultra-low-level jet stream on the windward slope of the eastern foothills, which was conducive to accumulation of dry and cold air for a long time and increasing thickness of the cold pad in lower layer. Then the warm and humid air flow was forced to lift to higher layer, which was conducive to condensation of water vapor and increase of snowfall. At the strongest period of snowfall, there was a northerly in lower layer, and an obvious “S” shape in middle layer for warm advection on the radial velocity chart of radar. At the upper level, there was a southwesterly jet maintaining for a long time, and the shear lines of northwest-southwesterly wind and southwest-southeasterly wind maintained at the same time. There was a good correspondence between the strong snowfall and the warm and humid jet from southwest climbing on the cold pad on the radar radial velocity chart, which was instructive for short-term forecast and early warning.

Key words: backflow blizzard, cold pad, dynamic frontogenesis mechanism, special terrain, radar echo


利用气象台站观测资料、赤峰市多普勒雷达(CINRAD/CA)观测资料、全球地形资料(水平分辨率1°×1°)以及NCEP的FNL(水平分辨率1°×1°)逐6 h再分析资料,对2019年3月20日内蒙古东南部春季暴雪天气进行分析。结果表明:这是一次典型回流降雪天气,低层925 hPa东北风急流与中层700 hPa西南急流形成明显的垂直风切变和温度差,产生强的动力锋生;低层辐合有利于垂直上升运动发展;850 hPa偏南风和偏东风水汽通道汇合于内蒙古东南部;850~700 hPa有强逆温层,冷暖空气剧烈交汇;南北向大兴安岭地形对东麓迎风坡东北风超低空急流有阻挡作用,有利于干冷空气长时间堆积,低层冷垫厚度加大,暖湿气流被迫抬升到更高层结,有利于水汽凝结和降雪加大;降雪最强时段,雷达基本径向速度图上低层为偏北风,中层有表征暖平流的“S”形回波,高层西南急流长时间维持,同时有西北风—西南风冷式切变线和西南风—东南风暖式切变线,雷达速度图上强降雪和西南暖湿急流在冷垫上爬升有很好的对应关系,这对短时预报预警有指导意义。

关键词: 回流暴雪, 冷垫, 动力锋生, 特殊地形, 雷达回波

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