Air mass characteristics as related to tropical wave precipitation over Lesser Antilles archipelago

The precipitations of tropical waves that cross the Caribbean archipelago are studied in this work by using satellite imagery and a rain gauge network. The data have been collected during the 1991 rainy season. Tropical waves are classified according the mean precipitation observed on the flat part of the island of Guadeloupe (Grande-Terre). According to the precipitation amount, one may distinguish three classes of tropical waves. The first class corresponds to waves that do not produce any rain or that break up during their passage over the Caribbean archipelago. Low and high precipitation amounts characterize respectively waves of the second and third class. Further the behavior of the air mass characteristics (relative humidity and wind fields) in relation to the tropical wave precipitation is analyzed. The analysis reveals that the relative humidity in the upper troposphere plays an important role in the development of precipitation in these waves. The behavior of the upper vertical profile of the mean static temperature is also consistent with our classification.