The large tropical disturbance that moved off the coast of Africa this week is slowly progressing across the eastern tropical Atlantic. It appears much less robust now, however, as part of the big plume of Saharan Dust just to its north has rotated into the circulation.
The National Hurricane Center is still giving it a very slight chance of organizing into a least a tropical depression over the next few days, but the highest likelihood is that it will continue west as simply a surge of moisture.
The disturbance is forecast to reach the vicinity of the eastern Caribbean islands next Wednesday plus or minus. We might feel an increase in tropical moisture in South Florida around next weekend.
The ocean water temperature in the tropical Atlantic between the Caribbean islands and Africa is still fairly cool, which is helping to throttle development of the system. That combined with the dusty air appears to be too much for the system to overcome.
It is very common to have plumes of Saharan dust stream across the eastern Atlantic this time of year. Normally, dust season is over by August, although it sometimes extends until the beginning of the peak part of hurricane season, which nominally begins August 15th.
When a disturbance has a big circulation like this one, it pulls in air from a large geographic area. As this one wrapped in air from the north, the dust came with it, which dried out the atmosphere just above the surface of the ocean.
Tropical systems run on warmth from the ocean and a moist atmosphere, neither of which this system has available at the moment.
Elsewhere, nothing is brewing, although we’ll keep half an eye on the western Gulf as a weak disturbance arrives there mid next week.
In the Pacific, Hurricane Enrique is just offshore of Mexico paralleling the coast. Warnings are up for the central coast as it brushes by.