2013年7月14日内蒙古河套地区极端暴雨天气诊断分析

Diagnosis Analysis of Extreme Rainstorm Process in Hetao Region of Inner Mongolian in July 14,2013

文章利用常规气象观测资料、加密自动站及分辨率1°×1°的NCEP再分析资料,对2013年7月14日内蒙古河套地区的一次极端暴雨过程进行诊断分析。结果表明:暴雨过程发生在有利的大尺度环流背景下,低层槽前西南气流及台风"苏力"和副热带高压外围的强劲的东南气流形成充足的水汽和能量供应,使得低层大气具有高温高湿性质,形成不稳定层结;冷空气侵入是暴雨触发条件;高低空急流耦合及地形抬升作用使得垂直运动强烈发展;低层湿位涡(MPV)的分布特别是湿位涡斜压项(MPV2)的分布对暴雨落区和增幅的预报具有一定的指导意义。

A diagnosis analysis of this heavy rainfall event is performed, using routine observational data, automatic meteorological station data, and NCEP 6-hour reanalysis data（1°×1°）. The result show that： the heavy rainfall takes place under the favorable largescale circumfluence. The southwest stream in front of the trough and the southeast stream between typhoon ＂suli＂ and the subtropical high transport warm and moist air to the precipitation area, and the low layer atmosphere have an unstable stratification with high temperature and high humidity; the cold air triggers the heavy rain. The coupling between a high level jet and a low jet, and the terrain makes the vertical strongly developing; the distribution of MPV in the low level atmosphere, especially MPV2, has a significant indication for the rainfall area.