TROPICAL DISTURBANCE APPROACHES THE CARIBBEAN ISLANDS, WHILE THE TROPICAL MOISTURE FEED RETURNS TO S

The National Hurricane Center has been tracking a small tropical disturbance – technically a tropical wave – just east of the southern Caribbean islands. The upper-level winds are not allowing the system to organize, so its effect on Trinidad and Tobago and the coast of Venezuela today and tonight will be as a moisture surge with some gusty squalls.

The system will continue west and may eventually contribute to the development a storm in the Pacific off the coast of Central America.

Just north of the disturbance and across much of the tropical Atlantic is an unusually strong plume of Saharan Dust. Computer forecast models show the dry, dusty air spreading across the Caribbean and into the Gulf of Mexico over the next week. That should keep the tropics quiet through next weekend and likely beyond.

Over the Carolinas, a giant upper-level low continues to spin, influencing the weather up and down the East Coast of the U.S. The tropical moisture channel feeding into that system has been just south of the Florida peninsula. The entire system – the circulation and its moisture feed – will slowly start to lift north later today increasing the tropical moisture over South Florida. Our chance of heavy thunderstorms will increase a bit day, with the moisture plume arriving in earnest tonight.

The core of the moisture channel is forecast to be over South Florida tomorrow and Friday meaning periods of heavy rain are expected. The concern will be for local flooding due to slow-moving tropical downpours, and for areas affected by multiple rounds of heavy rain.

Some heavy thunderstorms continue in the forecast over the weekend into next week, but as the pattern slowly changes and the moisture channel breaks down, more typical summer weather will return.

Look for a milky sky this weekend, the effect of the northern edge of that large plume of Saharan Dust.