主办单位:中国气象局沈阳大气环境研究所
国际刊号:ISSN 1673-503X
国内刊号:CN 21-1531/P

气象与环境学报 ›› 2011, Vol. 27 ›› Issue (6): 35-42.doi:

• 论文 • 上一篇    下一篇

东北冷涡背景下浙江省两次强降水过程的对比分析

罗玲1 胡亮2 何金海3 娄小芬1   

  1. 1. 浙江省气象台,浙江 杭州 310017;2. 中国气象局国家卫星气象中心,北京 100081;3. 南京信息工程大学大气科学学院,江苏 南京 210044
  • 出版日期:2011-12-30 发布日期:2011-12-30

Comparison of two rainstorm processes in Zhejiang province caused by northeast cold vortex

LUO Ling1 HU Liang2 HE Jin-hai3 LOU Xiao-fen1   

  1. 1. Zhejiang Meteorological Observatory, Hangzhou 310017, China; 2. National Satellite Meteorological Center, China Meteorological Administration, Beijing 100081, China; 3. School of Atmospheric Science, Nanjing University of Information Science and Technology, Nanjing 210044, China
  • Online:2011-12-30 Published:2011-12-30

摘要: 受东北冷涡西南部冷空气南下影响,2009年6月初浙江省连续发生了两次不同特点的强降水过程。利用常规气象观测资料、自动站资料、NCEP再分析资料及卫星TBB资料,对这两次东北冷涡背景下的强降水天气过程的大尺度环流背景、动力、热力及水汽输送条件进行了较全面的对比分析。结果表明:同在东北冷涡天气背景下,由于中低层温度场配置不同、上下游系统强弱不同,导致浙江省发生的天气不同。6月2日的降水是一次连续的区域性暴雨过程,雨带呈带状分布,以层状云降水为主,其低层为大范围的辐合,高层辐散,且低层辐合强于高层辐散。低空存在西南急流,为暴雨提供了重要的水汽和动力条件,大气层结比较稳定。6月5日强降水是一次强对流天气过程,降水分布不均匀,强度大,历时短,高、低空没有大范围的辐合辐散区,也没有低空西南急流,前期水汽条件不好,这次降水过程以热力作用为主,大气层结不稳定触发了强对流天气的发生,出现局地暴雨。两类暴雨的预报着眼点分别为:第1类区域性暴雨的预报重点为高层辐散低层辐合结构和低空西南急流;第2类局地性暴雨的预报重点为大气的不稳定度与东北冷涡后部冷空气的干侵入。

关键词: 东北冷涡, 区域性暴雨, 强对流天气诊断分析, 东北冷涡, 区域性暴雨, 强对流天气, 诊断分析

Abstract: Two rainstorm processes caused by northeast cold vortex occurred in the early June of 2009 in Zhenjiang province, and both had the different features. Based on the conventional meteorological data, data from automatic weather stations, the NECP reanalysis data and satellite images, the large-scale circumfluence background, dynamical and thermodynamic conditions, water vapor conditions of two processes were compared. The results indicate that weather situation is different because of the differences of temperature fields in middle and low levels and intensity of systems from upstream to downstream. The rainstorm on June 2nd is a continuously regional process and is mainly generated by stratiform cloud. The rain band distribution is zonal. There are large range convergence in low level and divergence in high level. The convergence in low level is stronger than the divergence in high level. The southwest jet steam exists in low level, which provides the important water vapor and dynamical conditions for rainstorm. Atmospheric stratification is stable.By comparison, the rainstorm on June 5th is a severe convection weather process. The distributions of precipitation are uneven, and precipitation intensity is strong and duration is short in this process. There are not large range convergence and divergence areas in high and low levels and southwest jet stream in low level. Water vapor conditions are poor in the early period of precipitation. This process is mainly generated by thermodynamic action, and unstably atmospheric stratification triggers the severe convection weather and results in the local rainstorm. The key points of forecasting are the structures of divergence in high level and convergence in low level as well as southwest jet stream in low level for the first regional rainstorm process, while those are atmospheric stratification instability degree and incursion of dry and cold air from the rear of northeast cold vortex for the second local rainstorm process.

Key words: Northeast cold vortex, Regional rainstorm, Strong convective weather diagnostic study, Northeast cold vortex, Regional rainstorm, Strong convective weather, Diagnostic analysis