A surge of tropical moisture will move over South Florida today and tomorrow. The moisture is on the north end of a tropical disturbance that extends from the Bahamas south across Cuba into the Caribbean Sea. The upper-level winds will not allow the disturbance to organize for now, but when it gets into the central and western Gulf of Mexico in a couple of days, the upper-air pattern is forecast to be more conducive for development.
The National Hurricane Center is watching for the possibility that it might organize into a tropical depression or tropical storm in the central or northwestern Gulf. It would arrive at the Texas or Louisiana coast at the end of the week. In any case, it doesn’t appear that it would have time to become very strong, based on the current forecasts.
Cloudiness and some bands of heavy thunderstorms are expected over the southern Florida peninsula with the moisture surge. Some areas may get heavy rain, while others get much less. The peak of the moisture is forecast to move through during the day today, but the tail of the system will still be pulling moisture over South Florida tomorrow.
This disturbance is just one in a series of pockets of moisture being pushed across the Atlantic by the strong flow around a well-defined area of high pressure that stretches from Europe across the ocean to the Southeast U.S. The flow on the south side of that high pushes along moist disturbances, dry patches, and sometimes Saharan Dust.
The dust has been washed out of the atmosphere over Florida by the recent rains, but the long-range computer forecast models show another big plume caught in the flow making it to the state in 5 or 6 days. Until then, off and on weak surges of moisture are expected to move through.
South of the big dust plume, a different tropical disturbance is showing signs of organization. This one, which moved off Africa as a tropical wave, is about halfway to the Caribbean islands. It has a brief window of time to develop into a tropical depression or tropical storm before the upper-level winds become hostile. The system is most likely to move through the southern Caribbean islands or along the northern coast of Venezuela as a moisture surge late in the week.
Otherwise, the Saharan Dust and the strong high-pressure system are expected to prevent any threatening systems from developing in the tropical Atlantic this week. Conditions in the Gulf are a bit more conducive for development, so we’ll keep an eye on that.