Characteristics of a Gust Front during a Severe Convective Weather Process in the Northeast Margin of the Tarim Basin
The characteristics of a gust front during a severe convective weather process in the northeast margin of the Tarim Basin in July 2016 is investigated based on hourly ground-based automatic weather station data,radar observation data and Weather Research and Forecasting(WRF)model high-resolution simulation data.The results showed that the strong convergent lifting effect at the front of the gust front caused the continuous triggering of multiple convective cells at the front of the gust front,most of which merged with the convective system behind it and further developed,resulting in the continuous developed and maintenance of severe convective weather.The analysis of the Moist Potential Vorticity(MPV)characteristics showed that the vertical shear of the horizontal wind at the front of the gust front caused a significant increase in the baroclinic component of the MPV during the rapid development period of the convective system,which enhanced the local Conditional Symmetric Instability(CSI)and provided an important instability condition for the development and maintenance of the convective system.The frontogenetical forcing required for the release of the unstable energy was mainly determined by the convergence and slantwise terms ahead of the gust front,while the horizontal deformation term near the gust front and the diabatic heating term aloft provided relatively weak contributions.