Chiang Mai Journal of Science

This research work concerns the numerical simulation of associated atmospheric dynamic processes and tracking of the tropical storm Vicente during September 14-18, 2005 by employing the Weather Research Forecasting Model (WRF). The model simulation successfully indicated that the storm Vicente developing in the South China Sea moved north-westward to Vietnam, Laos and Thailand and dissipated shortly after leaving Thailand. The cyclonic flow around low pressure area was precisely detected along the storm path according to the positive vorticity. The WRF outputs efficiently revealed the cyclonic flow around low pressure area, low level wind convergence, moist air updrafts, high relative humidity and rainfall during the storm evolution along the storm passage. With the lowest central pressure of 998 hPa but the strongest wind speed of 20 m.s^-1and the maximum vertical updraft of 0.25 m.s^-1, the storm Vicente actively intensified into the tropical storm on September 17, 2005 prior to making landfall. The simulated storm track was consistently supported by the MTSAT-IR satellite images while the maximum simulated and reported rainfall amounts of 80-100 mm.day^-1 for Thailand on September 18, 2005 were comparable.