THE ANALYSIS OF LOCAL FEATURES OF MCC ON SOUTHEAST TIBETAN PLATEAU

The convective weather occurs on Southeast Tibetan plateau frequently. The MCCs create large scope of thunderstorm and severe rainfall on local regions. Furthermore, they influences the weather in the middle reaches even lower reaches of the Yangtze River evidently. The notable characteristics explored through 16 MCC cases were analyzed on which formed on Southeast Tibetan plateau from June to September in 2001 and 2002: Firstly, The regions on which MCC generate prone areas were the Hengduan Mountains′regions about 100°E (West Region)and the Sichuan basin nearly 105°E(East Region),and the number of MCC which formed on lat er was more than on former. Secondly, these two kinds of MCCs had common feature s such as shorter lifetimes, smaller scale and quicker change than MCCs formed o n other regions like America and the lower reaches of the Yangtze River, but the time when MCC generated and decayed on which ER was later on WR, and the precip itation of MCC on which ER was more than on WR. At last, the evident difference existed between MCC on which WR and on ER in the circulations before their formtion, and there were largely discrepancies in the vertical constructions at mature stage. Enormous vapor transportation appeared at low middle layer before MCC generated on ER and evident positive vorticity circulations dominated in their mature stage. Also, the vertical wind change was little. Obviously, the MCC on ER was typical MCC noted; Contrarily, there were no evident vapor transportation at lowmiddle level before MCC formed on WR, and in their mature, positive vor t icity circulations were not prominent which related to latent heat released by l ess rainfall, but there were strong upper jet stream up MCC on WR. It is natural ly that some characteristics of MCC on WR were similar to severe storm on extent . In conclusion, the differences in two kinds of MCCs formed on Southeast Tibeta n Plateau were connected with the altitude of the area on MCCs generated.