Cause Analysis of Local Rainstorm in Zhongwei City on September 14-15,2021
[Purposes]The formation mechanism of the local rainstorm weather process in Zhongwei City on September 14-15,2021 was analyzed,so as to provide a reference for the forecast work of the sum-mer rainstorm and precipitation in Zhongwei City.[Methods]Using conventional ground observation data,Micpas ground high altitude situation field,high altitude humidity,T-lnP data,and hourly reanaly-sis data of ECMWF ERA5 reanalysis dataset from European Centre.the local rainstorm weather in Zhong-wei city was analyzed on September 14-15,2021.[Findings]The 584 dagpm moved north from 20:00 on the 13th to the highest from 20:00 on the 14th,and then began to pressure south,the rain belt moved south,and the western Siberian trough moved out of the central defender at 20:00 on the 15th. 200 hPa high altitude jet,500 hPa trough,700 hPa trough and low altitude jet,850 hPa low vortex shear and sur-face cold front cooperate with each other. The warm and humid air from the South China Sea and the Yel-low Sea around the typhoon continues to transport northward. The humidity conditions in the upper and lower layers are generally good,and the wet layer is deep. K index is stable between 33 and 34 ℃,and the low layer has warm low flow,while the moderate layer has cold flow and certain unstable energy;dy-namic conditions are good,strong rising movement center appears in this area at different times.And in the northern region,the middle and lower troposphere is a strong convergence zone,the upper layer is di-vergent,the ascending motion is strong,and the positive vorticity area is relatively deep.[Conclusions]The precipitation is characterized by long duration,wide range,small rainfall intensity and large cumula-tive rainfall. The upper trough has a clear backward structure,which is mainly stable precipitation. The ascending motion center and the deep wet layer are well coordinated,resulting in the local rainstorm weather.
NETL
NSTL
万方数据
