Mesoscale Observational Analysis of Isolated Convection Associated with the Interaction of the Sea Breeze Front and the Gust Front in the Context of the Urban Heat Humid Island Effect

An isolated convection was unexpectedly initiated in the evening of 1 August 2019 around Tianjin urban region (TUR), which happened at some distance from shear line lower level and preexisting to South, analyzed by using ERA5 reanalysis data observations surface weather stations, a S-band radar. The results show that, 42 min before initiation convection, atmospheric thermodynamic conditions TUR were favorable for although southerly vertical horizontal wind weak. A sea-breeze front approached continued move West, leading triggering context humid heat island (UHHI) effect. Subsequently, gust front, formed between cold pool away warm air UHHI, moved northward, collided with sea breeze resulting five reflectivity centers being merged convection’s development. Finally, split into two convections that disappeared 20:36 Beijing Time. developed interaction UHHI triggered effect, produced early convective storms south played vital role development convection.