2014年5月20日瓦房店市冰雹成因分析

Analysis of Hail Causes in Wafangdian City on May 20,2014

通过对1951—2009年瓦房店地区冰雹常规资料和冰雹灾情普查资料进行分析,利用MICPS常规观测资料、区域自动站观测实况、卫星云图、雷达拼图,结合瓦房店地区的地形特点,对2014年5月20日发生在瓦房店地区的冰雹天气进行分析研究。结果表明:朝阳、丹东、沈阳是辽宁省冰雹多发地,而瓦房店地区是辽宁省冰雹灾害多发地之一;瓦房店地区冰雹出现最多的是6月,其次是9月。高空槽线、低层切变线天气系统造成的辐合上升运动是此次强对流冰雹天气的触发机制;西南急流为短时强降水提供水汽,加大强降水的量级;"列车效应"是产生强降水的重要因素,促使冰雹、雷暴等短时强对流天气强度加大;地形、山脉迎风坡的抬升作用是此次冰雹天气发生的动力条件;背风波引起的上升运动,使河谷地区产生新的对流云,是该地区大面积降雹的主要原因。

Hail disaster conventional data and hail census data in Wafangdian City from 1951 to 2009 were analyzed.Using MICPS conventional observations,zone automatic observation stations live, satellite images,radar puzzles with topographic features,we analyzed the hail causes in Wafangdian City on May 20,2014.The results showed that Chaoyang,Dandong and Shenyang were hail-prone land,Wafangdian area was one of the hail disaster- prone area in Liaoning Province ;Wafangdian region had the largest hail in June,followed in September.Ascending movement caused by weather systems of upper trough line,low-level shear line radiation,is the strong convective weather trigger mechanism; Southwest jet provided water vapor for short-term heavy rainfall ,increased magnitude of heavy precipitation;＇ Trains effect＇ was an important factor to produce heavy rain ,prompted hail, thunderstorms and other severe convective weather short-term strength increase;Terrain and wind uplift mountain slope were the driving force of this hail weather conditions occur;upward motion caused by back storm, generated new convective clouds in valley were the main reason for the region＇s large hail.