On the Prediction of Tropical Cyclone Genesis Using an Operational Regional Prediction System

The genesis of tropical cyclones depends on atmospheric motions with a wide range of time and space scales. Grey (1979) and McBride et al. (1981) identified environmental conditions favorable for the development of tropical cyclones. While tropical disturbances exist all the time, only very few develop into tropical cyclones even under favorable environmental conditions. In this study, we evaluate the performance of the US Navy Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS®) in the prediction of tropical cyclone genesis in a three-day forecast range. The system configuration includes multi-nested grids to examine the impact of using cloud-resolving scheme. The U. S. Navy Operation Global Atmosphere Prediction System (NOGAPS) daily analysis is used as the lateral boundary condition to mitigate the limitation of a regional model. The dynamics and thermodynamics for the evolution of pre-genesis disturbances will be examined to understand reasons behind the forecast score of tropical cyclone genesis.