Hurricane Bill was expected to become a major hurricane in the next couple of days, with winds topping 110 mph as it moved on a track expected to be near Bermuda by the end of the week.
In the Caribbean Sea, forecasters said tropical depression Ana was poorly organized and weakening, but its heavy rains could threaten poverty-stricken Haiti, which was devastated by multiple storms last year.
It was too soon to tell if Bill would threaten the eastern coast of the U.S., said John Cangialosi, a meteorologist at the National Hurricane Center. It was not expected to threaten Florida.
"The system is certainly large and eventually will be a powerful hurricane," Cangialosi said. But colder waters and wind shear could weaken it as it heads farther north.
The cluster of three named Atlantic storms after two months with none was no indication of what the rest of the season could bring, forecasters said. The season's peak is mid-September.
Cangialosi said the way storm systems develop is chaotic: It can be quiet and then get busy. "This is certainly normal," he said.
Heavy thunderstorms rolled over the northeastern Caribbean as Ana, which had weakened to a tropical depression, approached the Dominican Republic and Haiti. Four tropical storm systems hit Haiti last year, killing almost 800 people and causing $1 billion worth of damage.
In Puerto Rico, rain from Ana flooded highways in the capital, San Juan, and three schools closed as a precaution in the northern coastal city of Arecibo. The U.S. territory was expecting 2 to 4 inches of rain.
Ana weakened from a tropical storm before passing over the Leeward Islands overnight and no damage was reported. Shops and offices opened as usual in St. John's, the capital of Antigua, which experienced only brief thunderstorms.
Ana was moving at a relatively fast pace, said Dave Roberts, a Navy hurricane specialist at the NHC. Although tropical storm watches had been canceled for the storm, Roberts said it could still be a big rain event for the island of Hispaniola, especially in higher elevations.
Along the Florida Panhandle, Tropical Storm Claudette quickly weakened after it made landfall at Fort Walton Beach, and was downgraded to a tropical depression with winds of about 30 miles per hour.
The storm wasn't expected to cause significant flooding or wind damage as it moved northwest into Alabama and Mississippi.
A man in his mid-20s died after being pulled from surf as Claudette approached Sunday. In Bay County, authorities searched for another man whose boat ran aground Sunday night, though they believe he eventually made it ashore. Neither man's identity was released.
After the storm passed east of Pensacola Beach on Monday morning, joggers and tourists seeking sea shells dotted the beach.
Far out in the Pacific, Hurricane Guillermo weakened to a tropical storm with maximum sustained winds near 60 mph. Guillermo was centered about 695 miles east of Hilo, Hawaii, and moving west-northwest near 18 mph.
Despite the storms, a warmer weather pattern called El Nino over the Pacific Ocean is generally expected to damper the formation of tropical storms in the Caribbean and Atlantic this year, said Brian Daly, a meteorologist with the National Weather Service in Mobile, Ala.
Forecasters revised their Atlantic hurricane season predictions after the first two months of the season passed without any named storms developing.
Associated Press writers Melissa Nelson in Pensacola and Kelli Kennedy in Miami contributed to this report.