To study the evolution of the mesoscale features, such as the activity of the mesoscale convective system (MCS), we have analyzed the high spatial resolution satellite data, including QuikSCAT 10-m wind and TMI/TRMM rainfall data. A conceptual model is proposed to describe the evolution of the mesoscale convections of the incipient disturbance due to the synoptic-scale trade wind surges. In addition, the formation of Typhoon Bolaven (2005) which is likely triggered by the trade wind surges is simulated using WRF (model resolutions of 60 km, 20 km and 4 km). Results show that WRF model can simulate reasonably well the evolution of the mesoscale convections and the development of the pre-TC disturbance. The external low-level forcing (associated with the trade wind surges) causes the MCSs of the disturbance to coil and lengthen. The merging of the strong vorticity patches (associated with the MCSs) results in the concentration and increase of low-level vorticity as well as the development of the disturbance. The vorticity and energy budgets will be analyzed using the model outputs to reveal the important processes of responsible for the formation of Bolaven.