The overall environment across the eastern Caribbean looks favorable to produce heavy rainfall and potential flooding starting later today and continuing through all of this weekend and possibly into at least the first half of next week. This heavy rainfall/flood threat may then spread into the central Caribbean as we get into the middle part of next week.
There are two areas that I have concern for potential heavy rainfall and flooding.
The first area is across the Lesser Antilles as a trough of low pressure slowly sinks from north to south across the Lesser Antilles next week. So, on Monday and Tuesday widespread showers and thunderstorms are expected across Guadeloupe, Dominica and Martinique.
The second area of concern is for some sort of tropical disturbance to push west-northwestward across the Caribbean next week. Current model guidance indicates that this disturbance may move into the central Caribbean by Tuesday and Wednesday spreading heavy rainfall and some squally weather across Hispaniola, Cuba and Jamaica. By late next week into next weekend, however, the model guidance diverges on where this disturbance may move towards.
The Canadian model guidance forecasts the development of a low pressure system over the northwestern Caribbean from this area of disturbed weather by next Friday. The Canadian model guidance then forecasts this low pressure system to move northwestward into the Gulf of Mexico next weekend.
The European model guidance forecasts heavy rainfall to shift into the central Caribbean by Tuesday and Wednesday and then spreading into the northwestern Caribbean by late next week and next weekend. This means that most of the heavy rainfall with a flood threat may impact Jamaica, the Cayman Islands, possibly the northeastern Yucatan Peninsula, parts of Hispaniola and Cuba from Tuesday through Friday of next week.
At this point, I think the area of greatest concern for heavy rainfall next week into possibly next weekend will be across Hispaniola, Jamaica, the Cayman Islands, Cuba and possibly the southern Bahamas. I don't believe the Canadian model's forecast of a low pressure system developing, which if the Canadian model is correct could try to become some sort of tropical system.