Hurricane Track Prediction with a New Barotropic Model

Abstract

Abstract A new barotropic prediction system for the tracks of tropical cyclones is presented. The system (referred to as WBAR) consists of an initialization procedure, a vortex enhancement scheme, and a shallow water model, formulated in a geographical coordinate system. During model initialization, the operational wind field analyses and forecasts of a global model are postprocessed to remove unwanted features such as mislocated weak vortices. Then a synthetic vortex, constructed from the information given by operational tropical cyclone advisories, is implanted at the observed position. In the vicinity of the storm, the wind fields are modified such that the total flow at the storm center corresponds with the observed translation velocity. Geopotential height is adjusted to the wind field by solving a nonlinear divergence equation without the tendency term. The numerical model integrates the shallow water equations in a storm-relative circular domain over a period of 72 h, using the postanalyses of glob...