江淮气旋北上造成黑龙江省强雨雪天气成因分析

使用常规观测资料、卫星云图、雷达回波资料、自动气象站降水量及0.25° ×0.25°的NCEP/NCAR再分析资料,对2018年11月89日发生在黑龙江省的强降水过程进行分析.结果表明:江淮气旋在向北移动的过程中不断加强,移入黑龙江省后发展到锢囚阶段,黑龙江省东部地区先后受暖锋和锢囚锋影响出现强降水;锋面附近有变压风辐...

Analysis on Causes of Heavy Precipitation Weather in Heilongjiang Province Affected by Jianghuai Cyclone Moving Northward

Based on the conventional observational data,satellite images,automatic observational precipitation and NCEP/NCAR 0.25°×0.25°reanalysis data,the extreme precipitation process in Heilongjiang Province during 8—9 November 2018 are analyzed.The major results are as follows:the cyclone over Changjiang-Huaihe River basin strengthened in the process of moving northward and developed into occlusion after moving into Heilongjiang.The severe precipitation occurred in eastern Heilongjiang affected by warm front and occluded front successively.The convergence of varied pressure wind near the front led to the intensification of convergence in the lower layer and the occurrence of heavy precipitation.During the warm frontal precipitation process,the wet symmetry instability occurred in the lower layer,and the stability of the middle and upper atmosphere was reduced,which was conducive to the maintenance and development of the ascending motion.Compared with the warm front,the occluded front made the lower atmospheres more convective and the middle and upper atmospheres less stable.The severe precipitation area was located in the strong convergence zone on the left front of low-altitude jet stream as well as the strong divergence zone on the right rear side of high-level jet of the north branch and the left front of high-level jet of the south branch.The section where the water vapor convergence zone of the middle and lower layers overlapped with the strong ascending motion was a severe precipitation zone.During the severe precipitation,there were two water vapor transport paths,the easterly jet and the southerly jet.After the two low-level jets got combined,they were transported into the severe precipitation area by the eastern boundary of the severe precipitation area.During the severe precipitation,the water vapor transport of the eastern boundary is the key to generate precipitation,accounting for 75.68%of the total water vapor input.