Analysis of the Severe Convective Weather Caused by Long-Live Cold Vortex in Inner Mongolian

Using the conventional detection,satellite images,T-log P and NCEP reanalyzes data(horizontal resolution 2.5°×2.5°),under the background of a cold vortex from 8 to 18 on June 2012,the route of the cold vortex and the cause of the severe convective weather in different areas of Inner Mongolia were investigated.The results show that:(1) the reasons for cold vortex's turning west were cold air from West Siberia and the transportation of vorticity to the back of the vortex.Turning west of the cold vortex is the main reason of long duration of the cold vortex,the rainstorm and continuous severe convective weather.The east region of Inner Mongolia was located in a tongue of high of potential temperature and its high gradient.(2) In the northeast of Inner Mongolian,severe convective weather happened when meso-micro scale convective systems strongly developed and consolidated,and maximum rainfall intensity happened when TBB(gradient of TBB) obviously decrease(increase),the ascending motion and water vapor convergence in the vertical direction of the windward slop were strengthened by terrain,which offer conditions for rainstorm.(3) In the southeast of Inner Mongolian,merging of several meso-micro scale convective systems continually lead the deep moisture air to the southeast of Inner Mongolian,and the water vapor was convergent strongly in the vertical direction.There also existed dry intrusion in the southeast,which provided instable condition for the severe convective weather.Low level jet and low level shear were the dynamic factor of the severe convective weather.The severe convective weather happened under the ascending branch of secondary circulation.