Analysis of a Wenzhou-Hitting Exceptionally Strong Rainstorm Associated with a Typhoon Inverted Trough in September, 1999

Using T106 numerical products, MM5 simulations in conjunction of Q-vector scheme-computed NCEP results, observations and satellite cloud images, study is undertaken of an exceptionally intense rainstorm event afflicting the Wenzhou region of Zhejiang province far away from the tropical storm center happening early on the morning of September 4, 1999 (TS9909).Evidence suggests that, like previously-studied typhoons landing in autumn south of Xiamen to the eastern part of Guangdong, TS9909 has an inverted trough in the central south of the coastal belt of Zhejiang province that produces the rainstorm from the meso convective complex (MCC) on the warm moist shear inside; the time and order of the magnitude of the rainfall are bound up with the development of the pattern of strong Q-vector divergence gradients during the event for the study area; the NE - SW coastline and the unique topography of the Yandang mountains inside the region are favorable for air lifting are the major contributors to the torrential rains.