Comparative analysis of two thunderstorm gale events triggered by wet microbursts over the Liaodong Peninsula

The study utilizes SA Doppler weather radar data from Dalian and Dandong, combined with surface observations and ERA5 reanalysis data, to conduct a comparative analysis of the synoptic background and mechanisms of two mild-wet downburst events over the Liaodong Peninsula: the first on September 11, 2020 (Event Ⅰ), and the second on September 10, 2021 (Event Ⅱ).Results indicate that both events occur under the influence of a Northeast Cold Vortex.Event Ⅰ is associated with a cold vertex transformed from a northward typhoon, while Event Ⅱ involves a cut-off low.Both events are characterized by unstable atmospheric stratifications of "upper-wet and lower-dry", with skew-T diagrams showing an upward-opening "bell-shaped" structure.Near-surface temperature lapse rates are nearly dry-adiabatic.The precipitable water content exceeds 30 mm.The lifting condensation level is low, with CAPE and DCAPE values being relatively small.The 0-6 km wind shear intensity is significantly stronger in Event Ⅱ than in Event Ⅰ.The thunderstorm gale events in both cases are induced by wet microbursts, with Event Ⅰ involving an isolated storm and Event Ⅱ embedded within a squall line system.In both cases, the Doppler radar reflectivity notches exceeding 45 dBz appear earlier at higher elevation angles than at lower elevation angles prior to the wet microbursts.