广西一次槽前型暖区飑线的中尺度分析  

A mesoscale analysis on a warm-sector squall line in front of the trough occurred in Guangxi

作　　者：林确略 邓雅倩 陈明璐 陆秋霖 苏尉宣 Lin Quelue;Deng Yaqian;Chen Minglu;Su Weixuan;Lu Qiutin(Yulin Meteorological Bureau, Yulin Guangxi 53700)

机构地区：[1]广西玉林市气象局,广西玉林537000

出　　处：《气象研究与应用》2018年第1期38-45,I0003,共9页Journal of Meteorological Research and Application

基　　金：玉林市气象局自立项目(2016[01]);中国气象局预报员专项(CMAYBY2015-057)

摘　　要：利用自动站加密观测资料、常规观测资料、NCEP资料以及FY2G、雷达资料,对发生于2016年4月22日的广西暖区飑线过程进行了中尺度分析。结果表明:(1)飑线移动快速(100km·h-1),主要引发湿对流天气(雷暴大风和短时强降雨);飑线过境前气压下降,过境时气温和露点骤降、气压涌升、风向突变、风速陡增,过境后气压再次下降;具有尾流低压、雷暴高压、飑锋和飑前低压等飑中系统特征。(2)此次暖区飑线是在500h Pa高空槽加深东移的大尺度背景下发生的,飑线A初始对流的触发与云贵准静止锋前的地面辐合线密切相关,飑线B初始对流则由红河与玉溪间的露点锋及其锋前西南风和东南风的辐合线所触发,对流触发后随高空槽和中层基本气流向东偏南方向移动发展,影响广西。(3)虽然没有冷锋伴随而下,此次暖区飑线依然是在较强的环境下维持,有较强垂直风切变、较高对流有效位能、层结曲线和露点曲线向上形成"喇叭"状配置(上干下湿对流不稳定);地面辐合线、边界层暖切对飑线的发展和维持有重要作用。By using intensive observation data of automatic station, conventional observation data, NCEP data, FY2 G data, and radar data, the warm-sector squall line occurred in Guangxi on April 22, 2016 was analyzed. The results showed as follows ： the squall line occurred in the front of high-level trough, areas near low-level jet and warm-sector areas were far away from ground stationary front.（1） The squall line moved at a high speed（ 100 km/h）, which caused wet convection weather（ thunderstorm gale and short-term heavy rain）. Pressure reduced before the squall line crossed; the temperature and dew point plunged, pressure surged, wind shifted, and wind speed jumped when the squall line passed however, the pressure reduced again after it passed. The squall line showed other characteristics of squall line mesosystem such as wake low, thunderstorm high, squall front, and pre-squall low.（2） The squall line occurred when the 500 h Pa high-level trough eastward was steepening. The trigger of initial convections of squall-A closely related to surface convergence line ahead of the Yungui quasi-stationary front, while initial convections of squall-B were triggered by dew-point front situated between Yuxi and Honghe,convergence line of southwest, and southeast wind ahead of the front. After that, the convections moved southeastward along with high-level trough and middle-level basic flow then influenced Guangxi.（ 3）Although moving without cold front, this warm-sector squall line maintained in favorable environment,such as strong vertical wind shear, high CAPE, ＂trumpet＂ shape of stratification curve, and dew-point curve composing（convective instability）. Additionally, surface convergence line and warm shear on the boundary layer were also important for developing and maintaining of the squall line.

关 键 词：暖区 飑线 地面辐合线 云贵准静止锋 

分 类 号：P49[天文地球—大气科学及气象学]