Numerical Prediction of Tropical Weather Systems

Abstract

A multilevel primitive-equation model has been designed for regional weather forecasting in the Tropics. Several experimental forecasts have been made on hurricane movement and development and on a nondeveloping tropical weather system. Forecasts of the movement of hurricane Celia were slightly slow and somewhat south of the actual track. Some intensification was forecast as Celia moved into the central Gulf of Mexico, but the model did not predict explosive deepening. Grid spacings of 75 and 150 km were used.In the nondeveloping case, no deepening was forecast. Areal distribution of the predicted rainfall was good, but the amounts were too light. Forecasts have been made with hand-analyzed input and with interpolated data extracted from the National Meteorological Center's objective analyses.Now at the National Hurricane Center, National Weather Service, NOAA, Coral Gables, Fla.