J4 ›› 2010, Vol. 28 ›› Issue (1): 81-86.

• 论文 • 上一篇    下一篇

河西走廊一次大雨天气诊断分析

滕水昌殷玉春   

  1. 1.甘肃省永昌县气象局,甘肃 永昌 737200;2.甘肃省武威市气象台,甘肃 武威 733000
  • 收稿日期:2009-08-27 修回日期:2009-10-21 出版日期:2010-04-01 发布日期:2010-04-01
  • 作者简介:滕水昌(1966-),男,甘肃武威人,工程师,主要从事天气预报分析研究.E-mail:yctsc@126.com

Diagnosis of a Heavy Rain Occurred in the Hex i Corridor

 TENG Shui-Chang1, YAN Yu-Chun2   

  1. 1. Yongchang M eteorological S tation of Gansu Province, Yongchang 737200, China;2. W uweiM eteorological B ureau of Gansu Province, W uwei 733000, China
  • Received:2009-08-27 Revised:2009-10-21 Online:2010-04-01 Published:2010-04-01

摘要:

 对2009年8月18日发生在甘肃省河西走廊中部区域性大雨从天气形势、物理量场、水汽条件、卫星云图特征进行了综合分析,发现500hPa巴尔喀什湖至新西伯利亚阻高的发展使得脊前冷槽南压加强,为这次区域性大雨形成提供了冷空气来源,副热带高压明显西升北抬为大雨形成提供了充足的水汽来源;700hPa低空低涡的辐合为大雨产生提供了必要的上升运动,并促使对流不稳定层结的产生和发展。同时发现,中低层不稳定能量触发,在大尺度锋面降水云系中产生中尺度对流云团活动,是造成局地雨强较大的主要原因。高低空螺旋度“上负下正”的配置,对强降水的预测和落区有良好的指示作用。

关键词: 大雨, 物理量场, 天气诊断

Abstract:

regional heavy rain occurred in the middle of Hexi Corridor on August 18 2009 was analyzed from the synop tic situation,physical quantity fields, water vapor conditions and satellite image’s features. Results show that the development of 500 hPa blocking high from Balkhash Lake to Novosibirsk made the cold trough before the ridge strengthen and extend south, and it p rovided the cold air for this regional heavy rain. The western and northern extension of the subtrop ical high p rovided adequate water vapor for the rain. The convergence of the vortex at the level of 700 hP resulted in increase of upward airmovement, which p romoted convection unstable stratification emergence and development. The low and middle level instability energy triggered mesoscale convective activities in large -scale frontal rainfall cloud system , which was the main reason for this heavy rain event. The configuration of negative helicity at up level and positive helicity at low level has a good indication for forecasting heavy rainfall and rainfall area.

Key words: heavy rain, physical quantity field, diagnosis

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