This chapter studies two Tropical cyclone (TC) cases, Typhoon Dan (1999) and Typhoon Ketsana (2003), and discusses their rates of formation and relationship with the mesoscale convective activities through examining the numerical simulations of the two cases. Many TCs generate from a single mesoscale convective System (MCS) or multiple MCSs; the physical processes under these two patterns are found to include dissipation of convection leading to new eruptions of deep convection located near the edge of the dissipating convection core, ingestion of nearby convection, merging of multiple MCSs into one MCS, and merging of deep convection within the MCS associated with the aggregation of vorticity in early development stage of TCs. How these activities lead to the formation of Typhoon Ketsana has been diagnosed. The diabatic heating associated with these convective activities also help to form the TC warm core. The relationship between the rate of TC formation and early development and convection energy consumption is discussed.
Part of the book: Tropical Cyclone Dynamics, Prediction, and Detection