A Numerical Study of the Genesis of Tropical Storms Observed during the FGGE Year

Abstract

Abstract This study utilizes the First GARP Global Experiment's (FGGE) analyzed dataset and a relatively fine scale regional model in combination to investigate the feasibility of numerically simulating tropical disturbances during the FGGE year, 1979. Four different cases were investigated including a cyclone. TC-17, in the Indian Ocean, a developing hurricane, David, and a nondeveloping wave in the Atlantic, and a multi-storm case, Tip and Roger, in the Pacific. The results were promising when using ECMWF FGGE data in that simulations of genesis or nongenesis were achieved in the three developing cases and in the one nondeveloping case. The accuracy of the intensification rates varied from case to case. For example, in the simulation of TC-17, the maximum low level winds were simulated to be ∼45 m s−1 while observations indicated winds of only 22 m s−1. However, in the case of David, the maximum winds increased at a slower rate than observed, while in the case of Tip the slow intensification rate was co...