Precipitation rate of tropical maritime convective clouds as related to the coldest cloud top temperatures

The maximum rain rates produced at ground level in the island of Guadeloupe (French West Indies) by 75 cloud systems during 1994 have been studied in relation to the coldest cloud surface temperatures obtained by using METEOSAT 3 infrared satellite imagery. The analysis reveals that the cloud systems in which warm rain production mechanisms (collision and coalescence) are dominant may produce non negligible rain rates and should therefore be taken into account in the algorithms that relate the precipitation rates to temperature of the coldest cloud surfaces. Further, the orographic precipitation enhancement due to the mountainous part of the island has been estimated in terms of a rain rate amplification coefficient. It appears that high amplification coefficient values correspond to low rain rate values over the flat part of the island and vice versa. Two algorithms that take into account the above analysis conclusions and allow the estimation of the maximum and mean rain rates over the flat part of the island have been developed.