Three areas of concern over the Atlantic basin on this Wednesday afternoon.

The first is a tropical wave currently located over the central Caribbean Sea. The associated showers and thunderstorms have become more concentrated today, and some gradual development of this system is possible during the next day or so while it moves westward at about 15 to 20 mph across the central Caribbean Sea. After that time, the wave is forecast to move more slowly west-northwestward, and a tropical depression is likely to form later this week when the system reaches the northwestern Caribbean Sea. It has a medium (60 percent) chance of formation during the next 48 hours and a high (80 perecent) chance during the next five days.

The second is an elongated area of low pressure located about 1000 miles east of the Windward Islands, producing a concentrated area of showers and thunderstorms. Although recent satellite-derived wind data indicates that the low is not well-defined, environmental conditions are conducive for further development, and a tropical depression is expected to form during the next day or two while the system moves generally west-northwestward at 15 to 20 mph across the central and western portions of the tropical Atlantic. Interests in the Lesser Antilles should monitor the progress of this system. It has a high (90 percent) chance of formation during the next 48 hours and five days.

The third is a large area of showers and thunderstorms located over Guinea and Sierra-Leone, Africa, associated with a vigorous tropical wave. Environmental conditions are expected to be conducive for some development of this system while the wave enters the extreme eastern Atlantic on Friday. By early next week, however, conditions are forecast to become less favorable for tropical cyclone formation while it moves west-northwestward at 15 to 20 mph toward the central tropical Atlantic. It has near zero chance of formation during the next 48 hours and low (30 percent) chance during the next five days.