ANALYSIS OF MESOSCALE CONVERGENCE CHARACTERISTICS OF A SEVERE CONVECTIVE WEATHER PROCESS ON 23 JUNE 2011 ALONG THE HUAIHE RIVER

There occurred a severe convection process on 23 June 2011 along the Huaihe River. From 0800BT 23 to 0800 BT 24 June 2011, the rainfall amount of 12 counties(or cities) within the 24 h exceeded 100mm, and the measured rainfall amount in the system center of Mingguang reached 186 mm in 24 h. With multiple meteorological data, including conventional meteorological observations, automatic stations, 1 °×1 °NCEP/NCAR reanalysis data, MTSAT, doppler radar data, and the numerical simulations of WRF, we studied the weather patterns associated with it and conducted a comprehensive analysis and numerical simulation using the mesoscale model WRF. Results show as follows:(1) The convective cells moved from the southwestern saddle field, resulting in the enhancement and maintenance of the convective system.(2)The thunderstorm gale was caused by the descending of the upper-level cold air.(3) The convective cells came from three different directions. Firstly, the convective cells occurred in the southwestern saddle field,and then moved to the Huaihe river region along a meso-and low-level southwest current. Secondly, the convective cells occurred in the south current at the edge of subtropical high, and then moved to the Huaihe river region along the south current. Thirdly, the convective cells were triggered ahead of the upper trough and moved to the Huaihe river region along the northwest current.(4) Meso-and low-level shear line and surface meso-scale convergence line organized and intensified the convective cells.