Tropical Storm Erika is approaching the Leeward Islands from the Atlantic, and forecasters say it may gain strength.
The storm's maximum sustained winds remained at 40 mph Tuesday as South Florida was put in the cone of uncertainty in the latest National Hurricane Center advisory.
NHC officials said Air Force and National Oceanic and Atmospheric Administration planes found Erika poorly organized Tuesday.
U.S. & World
A Tropical Storm Warning is in effect for Anguilla, Saba, St. Eustatius and St. Maarten. A Tropical Storm Watch is in effect for Montserrat, Antigua and Barbuda, St. Kitts and Nevis, Guadeloupe, St. Martin, and St. Barthelemy, Puerto Rico and the U.S Virgin Islands, and British Virgin Islands.
A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours.
Erika was centered about 495 miles east of Antigua and was moving west near 18 mph.
Slow strengthening is possible over the next 48 hours and the center of Erika was expected to be near the Leeward Islands Wednesday night and early Thursday.
Meanwhile, Tropical Storm Ignacio has strengthened in the eastern Pacific with top sustained winds of 40 mph (65 kph) as it moves westward some 1,525 miles (2,455 kilometers) east-southeast of Hilo, Hawaii.