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Barbados tropical wave better organized

By: Dr. Jeff Masters, 1:10 PM GMT on July 12, 2006

A tropical wave about 150 miles east of Barbados has become better organized this morning. A sudden burst of intense thunderstorms developed between 6am and 10am EDT, and a surface circulation is now apparent near 12.5N 57W on visible satellite imagery. The center is exposed on the west side due to strong upper-level winds from the west, and the latest 8am EDT winds shear analysis from the University of Wisconsin showed wind shear of 10-20 knots over the disturbance. Weaker upper-level winds just to the disturbance's south have pushed northwards, creating an opportunity for the system to develop. (The University of Wisconsin wind shear product is updated every three hours, and the 11am EDT analysis is due out around 1 pm EDT).

The system is moving west at 15 mph, and should bring heavy rain and wind gusts of 30-40 mph to Barbados this afternoon and St. Vincent and St. Lucia tonight. It will be very interesting to see what the wind and pressure readings look like from these islands today. It's possible that this system will become a tropical depression later today, but I doubt that it will make it to tropical storm status, despite its healthier appearance on satellite imagery this morning. The area covered by intense thunderstorms is very small, and it would take only a modest increase in wind shear to tear the system apart. There's plenty of wind shear to the system's north and west, and the chances of it surviving beyond Thursday are low.


Figure 1. Latest satellite image of the tropical wave approaching the Lesser Antilles Islands.


Figure 2. Model forecast tracks for the tropical wave approaching the Lesser Antilles Islands.

The rest of the tropics are quiet. A tropical wave is pushing ashore into South Florida, and will bring heavy rains there. An upper-level low is spinning over the central Gulf of Mexico, but this low is not expected to develop, due to high wind shear. None of the major computer models are forecasting any tropical storm formation in the Atlantic for the next six days. Wind shear is forecast to remain high over most of the tropical Atlantic this week, then gradually decrease for the remainder of the month.

I'll have an update on the Barbados system this afternoon.

Jeff Masters

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.