90L: Shower and thunderstorm activity associated with an area of low pressure located several hundred miles south of the Cabo Verde Islands continues to gradually become better organized. Environmental conditions are conducive for additional development, and a tropical depression or tropical storm is likely to form later today or tonight while the disturbance moves west-northwestward at 10 to 15 mph over the eastern tropical Atlantic. Additional information on this system, including gale warnings, can be found in High Seas Forecasts issued by Meteo France.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.
91L: Showers and thunderstorms remain disorganized in association with a a broad and elongated area of low pressure located several hundred miles southwest of the Cabo Verde Islands. Although environmental conditions are generally conducive for development during the next day or so, interaction of this system with the low pressure area located to its east is likely to hinder development after that time. The system is forecast to drift west-northwestward over the next few days.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...medium...50 percent.
...AIR FORCE HURRICANE HUNTERS FIND SAM FLUCTUATING IN STRENGTH...
At 5 a.m. AST, the center of Hurricane Sam was located over the Atlantic Ocean about 455 miles (730 km) east of the northern Leeward Islands. Sam is moving toward the northwest near 9 mph (15 km/h), and this general motion with an increase in forward speed is expected during the next couple of days. A turn toward the north is forecast by Friday. On the forecast track, Sam will pass well to the east and northeast of the northern Leeward Islands through tonight.For more information, check the daily Tropical Weather Outlook, click here