怀化市汛期短时强降水特征分析  

Analysis on the characteristics of short-term heavy precipitation in flood season in Huaihua City

作　　者：王光明[1] 王文闻 王强[1] 梁晓梅 WANG Guangming;WANG Wenwen;WANG Qiang;LIANG Xiaomei(Huaihua Meteorological Office of Hunan Province,Huaihua 418000,China;Huitong Meteorological Office of Hunan Province,Huitong 418300,China)

机构地区：[1]湖南省怀化市气象局,湖南怀化418000 [2]湖南省会同县气象局,湖南会同418300

出　　处：《中低纬山地气象》2020年第1期54-59,共6页Mid-low Latitude Mountain Meteorology

基　　金：湖南省气象局预报员专项(XQKJ18C003):暴雨短时强降水自动监测与预警

摘　　要：利用怀化市11个国家站和403个区域站2012—2017年4—9月逐小时降水量资料以及NCEP资料,采用统计分析方法分析了怀化市短时强降水的时空分布特征,同时采用天气诊断分析方法对产生短时强降水的天气系统进行归纳,得到如下结论:怀化短时强降水的频数年际变化大,发生频次最多的是2017年,达103次,最少的是2013年,仅35次,且主要集中在5—7月,6月最多,4月最少;其日变化呈单峰型,4—10时最易发生短时强降水,峰值出现在08时,11—23时为低发时段。短时强降水的频数高、日数多,空间分布表现为北部多,中南部少;2/3的短时强降水极值对应等级为50~79.9 mm·h^-1,最大值为129.9 mm·h^-1,雪峰山西侧(会同、洪江、溆浦)以及辰溪境内最易发生≥80 mm·h^-1的短时强降水。产生短时强降水的天气系统主要有低涡型和切变线型。当850 hPa低涡在关键区域活动时,低涡型短时强降水主要集中在低涡偏东偏南位置,而切变线型短时强降水主要集中在850 hPa切变线偏南1~3个纬距内,尤其是与低空急流出口区左侧叠加的区域。Based on the hourly precipitation data of 11 national stations and 403 regional stations of Huaihua City,Hunan Province during April to September from 2012 to 2017 and the NCEP data,the statistical analysis method was used to analyze the temporal and spatial distribution characteristics of short-term heavy precipitation,and the weather system that produced short-term heavy precipitation was summarized by means of weather diagnosis.The results show that the frequency of short-term heavy precipitation in Huaihua has changed greatly from year to year,the highest is in 2017(103 times)ant the least is in 2013(35 times).It is mainly concentrated in May to July,which was highest in June and lowest in April.The daily variation of the short-term heavy precipitation is unimodal,and is most likely to occur at 4 to 10 o'clock,with peaks occurring at 8 o'clock and 11 to 23 hours being low-rising periods.The spatial distribution of short-term heavy precipitation is more in the north and less in the south-central;2/3 of short-term heavy precipitation extreme value corresponds to 50~79.9 mm·h^-1,and the maximum value is 129.9 mm·h^-1.The west of Xuefeng Mountain(include huitong,Hongjiang,Zhapu)and Chenxi are easy to occur Short-term heavy precipitation that the strength is above 80 mm·h^-1.The types of low vortex and shear line are the main weather systems that produce short-term heavy precipitation.Weather systems that produce short-term heavy precipitation mainly have low vortex and shear line types.When the 850 hPa low vortex is active in key areas,the low vortex short-term heavy precipitation is mainly concentrated in the southeast of the low vortex,while the short-term strong precipitation in the shear line type is mainly concentrated in the south of the 850 hPa shear line,especially the area superimposed on the left side of the low-level jet exit area.

关 键 词：短时强降水 特征 低涡 切变线 

分 类 号：P426.6[天文地球—大气科学及气象学]