800 AM EDT Thu Aug 18 2011
For the North Atlantic...Caribbean Sea and the Gulf of Mexico
1. Satellite imagery indicates that shower activity associated with a tropical wave located about 200 miles south-southwest of Jamaica is becoming better organized. Surface observations across this region also indicate that pressures are falling. If current trends continue a tropical depression could form later today or tonight as the system moves generally westward at around 15 mph. This system has a high chance 80 percent of becoming a tropical cyclone during the next 48 hours. Interests along the coasts of Honduras, Nicaragua, Belize, and the eastern Yucatan Peninsula should monitor the progress of this disturbance. An Air Force Reserve unit aircraft is scheduled to investigate the wave this afternoon.
2. A large tropical wave located about 875 miles west of the Cape Verde Islands continues to produce limited shower activity. Significant development is not likely during the next couple of days. However...environmental conditions could become more conducive for development after that time. This system has a low chance 10 percent of becoming a tropical cyclone during the next 48 hours as it moves westward at 15 to 20 mph.
Elsewhere tropical cyclone formation is not expected during the next 48 hours.