台风“温比亚”引发豫东“18.8”极端降水的特征与成因分析

利用多源气象资料,对台风“温比亚”引发豫东降水的极端性特征及极端降水产生机制进行分析,提炼预报着眼点。此次降水是河南继驻马店“75·8”暴雨之后的又一次罕见特大暴雨,表现为过程雨量极大、破极值站数最多、降水强度极大、强降水时段集中的特征。结果表明：（1）高低空系统耦合为特大暴雨的发生发展创造了良好的环境条件,极端降水的产生主要受台风北侧螺旋云系影响,并有持续不断的强回波单体在同一个地点移动,冷空气与台风环流相互作用是重要的预报着眼点,重点分析台风和副热带高压的相对运动及西风带对台风的引导作用。（2）河南东部水汽输送条件一直处于较好的状态,这是降水维持较长时间的重要因素,急流中心区域和强度的变化对降水量多少有指示意义。（3）豫东地区对流不稳定和斜压不稳定均比较明显,低层MPV1<0、MPV2>0的区域与强降水落区有较好的对应关系。（4）强辐合中心位于台风中心的北侧,降水强度与辐合强度有较好的对应关系,螺旋度大值区分布对强降水的分布区域有较好的指示意义。

Analysis on the Characteristics and Causes of

Based on the multi-source meteorological data, the extreme characteristics and the mechanism of extreme precipitation in Eastern Henan caused by Typhoon "Rumbia" are analyzed, and the forecast focus is refined. This precipitation is another rare rainstorm in Henan after the "75.8" rainstorm in Zhumadian. It is characterized by the maximum process rainfall, the maximum number of extreme breaking stations, the maximum rainfall intensity, and the concentration of heavy rainfall periods. The results show that: (1) the coupling of high and low altitude system creates good environmental conditions for the occurrence and development of heavy rain. The generation of extreme precipitation is mainly affected by the spiral cloud system on the north side of the typhoon, and there are continuous strong echo cells moving in the same place. The interaction between cold air and typhoon circulation is one of the important prediction focuses. The relative motion of typhoon, subtropical high and the guiding effect of westerly belt on typhoon are mainly analyzed. (2) The water vapor transport condition in the east of Henan province has been in a good state, which is an important factor for the precipitation to maintain a long time. The change of the jet center area and intensity have an indicative significance for the amount of precipitation. (3) The convective instability and baroclinic instability are obvious in the east of Henan Province. The areas with mpv1 < 0 and MPV2 > 0 in the lower layer have a good correspondence with the areas with strong rainfall. (4) The strong convergence center is located on the north side of the typhoon center, and the precipitation intensity has a good corresponding relationship with the convergence intensity. The distribution of the helicity high value area has a good indication for the distribution area of the strong precipitation.