摘要
利用常规观测资料、多普勒天气雷达拼图资料与NECP再分析资料,对2016年9月15—16日发生在"莫兰蒂"(1614号)和"马勒卡"(1616号)双台风形势下的长三角地区大暴雨过程的成因进行了诊断分析。结果表明:此次暴雨过程发生在台风倒槽的顶端,暴雨区与对流层中低层辐合区和中高层高空急流右后侧辐散区相对应;"莫兰蒂"台风外围的丰富水汽与来自热带洋面"马勒卡"台风外围源源不断输送的水汽叠加,导致长三角地区降雨强度远大于"莫兰蒂"登陆前后阶段的降雨强度;苏皖地区高空槽后冷空气侵入,在浙江到上海沿海地区形成东北—西南向温度锋区,以及浙江中北部海陆交界地带特殊山脉地形的强迫作用,使得中尺度对流系统(MCSs)发展维持;长三角强暴雨区边界水汽通量收支变化与暴雨强度变化对应关系较好,且有6～12 h的提前量,对强降雨预报有一定的指示意义。
Using datasets of conventional observations,the regional mosaics of Doppler weather radar and NCEP/NCAR reanalysis,we have conducted a diagnostic analysis of the cause for an extremely heavy rainfall event under binary typhoons pattern occurred in Yangtze River delta from September 15 to 16 in 2016.The results indicate that the heavy rainfall areas of this event locate in the top of inverted trough of the No.1614 TC"Meranti"after it landed,and are corresponding with the convergence zone in the lower and middle troposphere and the divergence zone at the right rear side of high-level jet in the upper troposphere.The overlay of the abundant water vapor around Typhoon"Moranti" and the continually water vapor coming from the periphery of Typhoon"Malecas"over the tropical ocean results in the rainfall intensity in the Yangtze River Delta far greater than that before and after the landfall of Typhoon"Moranti".A northeast-southwest temperature front zone forms along the coast of Zhejiang to Shanghai with the intrusion of cold air behind the high-altitude trough in Jiangsu and Anhui province,and a forcing effect of the special mountain terrain produces in the sea-land junction zone in the north-central part of Zhejiang province,which significantly promotes the development and maintenance of the mesoscale convective system (MCSs).The variation of water vapor flux budget in the four boundary of the heavy rainfall area in Yangtze River delta is well corresponding with to the change of heavy rainfall intensity,and the former varies 6-12 hours in advance with respect to the latter,which can be an indicator for the forecast of severe precipitation.
作者
刘晓波
储海
LIU Xiaobo;CHU Hai(Shanghai Central Meteorological Observatory,Shanghai 200030)
出处
《暴雨灾害》
2019年第2期97-106,共10页
Torrential Rain and Disasters
基金
国家自然科学基金项目(41475040)
中国气象局预报员专项(CMAYBY2017-023)
关键词
暴雨
双台风
台风倒槽
水汽输送
高空急流
中尺度对流系统
heavy rainfall
binary typhoons
inverse trough of typhoon
water vapor transportation
upper level jet
MCSs
