Comparative Analysis of Two Severe Convective Gale Weather in Typhoon Periphery
To improve the forecasting and warning capability of severe convective gale associated with typhoon,this paper uses the conventional meteorological observation data and ERA5 reanalysis data in comparing and analyzing the circulation background,environmental conditions and radar echo characteristics of two typhoons with great differences in causing the typhoon-periphery severe convective gale weather in Guangxi on July 31,2016 and July 31,2020.The results show that:(1)The main impact system of the former was the easterly wind fluctuation on the south side of the subtropical high and the northwest side of the typhoon,while the main impact system of the latter was the inverted trough of the typhoon.Under the influence of the peripheral circulation of the typhoon,the convergence of near-surface winds was conducive to the initiation of convection.(2)Favorable moisture conditions and unstable vertical structure provided good ambient conditions for the occurrence and development of the severe weather.The triggering mechanisms of the two events were slightly different,and the difference in the position of the convergence line led to different initial convective locations and different impact ranges in Guangxi.(3)The differences in CAPE values and DC APE(600 hPa)values indicated that the convective development potential of the former was stronger than that of the latter,and the associated weather phenomena were also different.(4)Bow echoes of radar echoes and rear inflow jet streams brought about strong wind weather.The decreasing height of echo top and maximum reflectivity factor before the occurrence of strong winds indicated the presence of gales.The different moving speeds of storm cells also resulted in different forces of strong winds.
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万方数据
