两次粤东春季强对流天气过程的对比分析  

Comparison and Analysis of Two Processes of Severe Spring Convective Weather in Eastern Guangdong

作　　者：丁丽佳 DING Li-jia(Meteorological Bureau of Chaozhou City,Chaozhou 521011)

机构地区：[1]潮州市气象局,广东潮州521011

出　　处：《广东气象》2018年第5期35-38,61,共5页Guangdong Meteorology

摘　　要：利用常规地面、高空探测资料,对2015年4月20日、2017年4月21日粤东两次强对流天气过程的天气背景、水汽条件、不稳定条件、触发机制等进行对比分析,探讨形成不同强对流类型的可能原因。结果表明:2次强风暴天气都出现在有利于对流发生的天气背景下,具有较高的不稳定条件、对流触发机制,水汽较充足,主要的不同在于:第1次过程湿层浅薄、辐合层次较低,但低层存在强烈的风速切变,同时存在中层干冷空气向下入侵的现象,因此对流发展激烈,出现了明显的冰雹大风天气,但是由于持续时间较短,水汽不足,强降水出现时间较短,累积雨量小;第2次过程湿层深厚、辐合层次较高,但低层风速切变不是很大,没有中层干冷空气向下入侵的现象,因此对流发展相对较慢,没有出现大范围的冰雹大风天气,但是由于持续时间长,强降水出现时间长、累积雨量大。With conventional data of the surface and upper-level sounding, the weather background, water vapor, instability, and triggering mechanism are compared and studied for two processes of severe convective weather in the eastern part of Guangdong province on April 20 and 21, 2015 to probe into the possible causes for different types of convection. The result is shown as follows. The two processes all took place under favorable weather background for convection, which were marked by high instability, triggering mechanisms for convection and sufficient amount of water vapor. Their main difference is presented below. For the first process, the wet layer was shallow and the converging level was relatively low, though intense wind-speed shear existed at the low level with downward intrusion of cold and dry air from the middle level, resulring in vigorous development of the convection and significant hail and gale. However, the intense rain did not last long nor accumulated much due to short duration and insufficient amount of water vapor. For the second process, the wet layer was deep and the converging level was relatively high, but wind-speed shear was not large at the low level and no mid-level dry and cold air intruded downward. As a result, convection developed slowly without extensive weather of hail and gale. However, it was marked by long duration of intense rain and large accumulated rainfall due to its long life cycle.

关 键 词：天气学 强对流 水汽 春季 粤东 

分 类 号：P44[天文地球—大气科学及气象学]