A REGIONAL SCALE ANALYSIS OF THE TRAJECTORY AND INTENSITY BEHAVIOR OF TROPICAL CYCLONES CROSSING THE CARRIBEAN ARCHIPELAGO (Formerly paper 3B.7)

The prediction of huricane trajectories and intensities is of key importance for the social and economical life of the islands of the Carribean archipelago. This regional scale prediction is complicated and requires the use of all modern meteorological prediction means, including very sophisticated large scale models (GCMs) and trajectories models, as well as empirical or semi-empirical procedures. The Carribean archipelago is concerned by two distinct categories of hurricanes, the first containing the Capo-Verde type hurricanes, while the second contains the so-called Barbados type hurricanes. Even if for both hurricane categories, at large scale, the predictions established seem to be quite accurate, at regional scale (Lesser Antilles),the somehow random trajectory and intensity behavior (related to the random character of the local meteorological conditions) adds some incertitude to the corresponding predictions. In this paper, an analysis of the trajectory and intensity behavior of some hurricanes that have crossed the Lesser Antilles archipelago between 1970 and 1999 is presented. This analysis is drown in relation to the regional low and upper atmospheric conditions and corresponding sea surface temperatures (1013mb isobar, presence or absence of upper troposheric vortices, vertical shear, low and upper level humidity). The analysis conclusions are used (a posteriori) in a attempt to predict the behavior of two recent tropical cyclones, Georges 1998 (Capo-Verde type) and Jose 1999 (Barbados type) when the crossed the Lesser Antilles archipelago.

Corresponding author : Constantin Pontikis Université des Antilles et de la Guyane Faculté des Sciences Exactes (L.P.A.T.) 97159 Pointe a Pitre Cedex Guadeloupe (F.W.I.)