豫南一次罕见极端特大暴雪过程诊断分析  

Analysis of a Rare Extreme Snowstorms in Southern Henan

作　　者：吴雪 WU Xue(Xinyang Tea Meteorological Key Laboratory,Xinyang 464000,China;Xinyang Meteorological Bureau,Xinyang 464000,China)

机构地区：[1]信阳茶叶气象重点实验室,河南信阳464000 [2]信阳市气象局,河南信阳464000

出　　处：《河南科技》2024年第13期97-101,共5页Henan Science and Technology

基　　金：中国气象局河南省农业气象保障与应用技术重点实验室预报员专项(KY202157)。

摘　　要：【目的】研究2018年1月4日豫南罕见极端特大暴雪成因。【方法】利用常规观测、多普勒雷达产品、FY-2F长波辐射和NCEP等多种气象资料,运用天气学诊断方法分析。【结果】结果表明:此次特大暴雪是在高空低槽东移的回流形势下,由700 hPa较强西南急流、850 hPa东南风急流、中低层切变线及较强东北风共同作用下的异常暴雪天气。【结论】低层西南急流和东南风急流把水汽输送到豫南地区,湿层深厚,并在暴雪区上方产生强的水汽辐合中心,为特大暴雪提供了有利的水汽条件;高低空急流耦合“抽吸作用”“天南地北”的风场配置、暖湿气流沿冷空气爬升的上升运动,均有利于极端暴雪的发生发展;豫南长时间处在中低层两切变线之间和水汽辐合上升区,强冷空气降温使得雨快速转雪,降雪持续时间长且强度大,是强降雪主要集中在豫南的重要原因;假相当位温高能舌下伸和锋区密集带对强降雪的开始和落区有很好的指示意义;OLR特征分析表明,OLR 3 h平均低值中心与3 h最大降雪中心明显的负相关关系。[Purposes]This paper aims to study the causes of a rare extreme snowstorm in southern Henan on January 4,2018.[Methods]Using various meteorological data such as conventional observations,Doppler radar products,FY-2F longwave radiation,and NCEP,the analysis was made by weather diagnostic methods.[Findings]The results indicate that this severe snowstorm was caused by the combined action of a strong southwest jet at 700 hPa,a southeast wind jet at 850 hPa,a shear line in the middle and lower layers,and a strong northeast wind under the reflux situation of a high-altitude trough moving eastward.[Conclusions]The low-level southwest jet and southeast wind jet transport water vapor to the southern region of Henan,with a deep wet layer and a strong water vapor convergence center above the blizzard area,providing favorable water vapor conditions for severe blizzards;the coupling effect of high and low altitude jet streams,the wind field configuration of"south and north",and the upward movement of warm and humid airflow climbing along cold air are all conducive to the occurrence and development of extreme snowstorms;the southern part of Henan Province has been located between the two shear lines in the middle and lower layers for a long time,as well as in the rising zone of water vapor convergence.The cooling of strong cold air causes rain to quickly turn into snow,and the snowfall lasts for a long time and is of high intensity,which is an important reason for the concentration of heavy snowfall in southern Henan;the false phase temperature,high-energy tongue extension,and dense front zone have good indicative significance for the start and fall of heavy snowfall;OLR feature analysis shows a significant negative correlation between the average low value center of OLR at 3 hours and the maximum snowfall center at 3 hours.

关 键 词：豫南 极端特大暴雪 OLR 诊断分析 

分 类 号：P458.1[天文地球—大气科学及气象学]