Analysis of the Tornado Circulation and Radar Characteristics in Hinggan,Inner Mongolia on 2 July 2021
Based on the conventional observation data,reanalysis data and radar data,the paper gives an analysis on the synoptic background,environmental conditions and radar characteristics of the EF3 tornado in Wenggenhailasugacha,Hinggan on 2 July 2021.The results show that the tornado occurred in the background of the northeast cold vortex.The direct impact system was the downward transverse groove behind the cold vortex.The tornado lay in a strong westerly airflow in the transverse trough,and it occurred in the overlapping area of the dry cold air behind the trough and the thin moisture layer at the lower level.The convective storm developed rapidly,fueled by the strong vertical wind shear and strong vertical upward movement.Prior to the occurrence of the tornado,the environmental conditions were unstable,accompanied with poor moisture conditions at the lower level and the obvious inversion layer in the middle and lower levels.As the tornado occurrence time approached,the relative humidity in the lower layer increased rapidly,while the equivalent potential temperature decreased significantly with height.Consequently,the stratification became unstable,and the wind speed increased with height.There was an obvious dry area in the upper level.The convection cell presented the typical structure of a supercell storm.Bounded weak echo zone,hooked echo and V-notch were identified in the primitive storm of this tornado.Before the tornado occurred,an cyclonic structure was found in the lower level,which was recognized as a mesocyclone.As it evolved and matured,it peaked in the middle level.In addition,prior to the tornado,the radar echo intensity was greater than 60 dBz,the height of maximum reflectivity factor kept growing,and the height of the echo top showed a continuous downward trend.
万方数据
维普
