Available online: December 29, 2020 , DOI:
An extreme gale event, hereinafter referred to as“3.21 Lingui gale event”, occurred in Lingui, Guangxi on 21 March 2019, Maximum gust of 60.3 m?s-1 (level 17) was recorded at the Lingui Observatory at 21:13. Based on the results of the wind damage survey with video and meteorological data, this paper presents that the high wind damage was caused by a strong microburst. Using data from conventional meteorological observations, intensive automatic weather station, radiosonde, Doppler weather radar, we have analyzed the environmental conditions and influencing systems of the“3.21 Lingui gale event”, with special emphasis on analyzing its cause based radar data and observational data. Results are as follows.(1) The “3.21 Lingui gale event” occurred under some favorable conditions such as Low-level warm and humid air flow is active, Mid-level significant dry layer and strong low-level vertical wind shear, and it is triggered by the development of convergence line at ground level and cold front.(2) “3.21 Lingui gale event” is caused by 2 in 1 supercell, Before the downburst occurs, the supercell develops to the most powerful stage, the maximum reflectivity core height (HGT) is more than 6 km, there is a medium intensity of the mesocyclone accompanied by the MARC value of 36 m?s-1. When the downbursts occurs ,reflectivity factor begins to weaken, the storm top drops high, HGT drops. when HGT drops sharply, a body sweep interval drops by 3.5 km, 17 thumps occur, and the low level 0.5 degrees elevation is observed in the high-altitude region of the cyclone, with a high radial dispersion value of 27 m?s-1, Mesocyclone has the strongest shear strengthening, the bottom high height rapidly dropped to less than 1km and other characteristics. (3) The occurrence of downburst is closely related to the dragging effect of extreme heavy precipitation and hail, When 1min rain strength of 3 mm, wind speed of more than 12 levels, 1min rain strong 6 mm, 17 degrees of extreme wind speed.