(CNN) -- Tropical Storm Rafael unleashed heavy rain and powerful gusts on the Leeward Islands on Sunday and could turn into a hurricane by Monday, forecasters said.
With sustained winds of 60 mph, Rafael could get even stronger as it bears down on several islands popular with tourists.
As of 5 p.m. ET, Rafael was centered about 185 miles (298 kilometers) northeast of San Juan, Puerto Rico, the National Hurricane Center in Miami said. The storm was moving north-northwest at 10 mph (16 kph) and was expected to turn northward by Monday.
A projection map shows Rafael headed toward Bermuda later this week.
Officials there issued a tropical storm watch Sunday and told residents that they expected the storm to affect the British territory on Tuesday.
While the National Hurricane Center predicted Rafael will stay well to the east of the Bahamas through Monday, it did warn of life-threatening surf conditions and rip currents on the eastward-facing beaches of the Bahamas over the next few days.
Tropical storm warnings that had been in effect for the U.S. and British Virgin Islands, St. Martin, Antigua, Barbuda, St. Kitts and Guadeloupe were discontinued Sunday morning.
Forecasters expect Rafael to leave between 4 to 6 inches of rain over the Lesser Antilles and Virgin Islands, with some pockets getting as much as 10 inches.
"These rains could cause life-threatening flash floods and mudslides, especially in areas of mountainous terrain," the hurricane center said.
The storm could hamper rescue efforts for two men and one woman whose small aircraft crashed Saturday morning about six nautical miles (seven miles) south of St. Thomas in the U.S. Virgin Islands, Coast Guard spokesman Ricardo Castrodad said. They were aboard a twin-engine Piper PA-23 that left St. Croix destined for St. Thomas, according to Federal Aviation Administration spokeswoman Kathleen Bergen.
Rescue crews from the Coast Guard and U.S. Virgin Islands Department of Natural Resources saved one female passenger, Valerie Jackson, who told them three others were still unaccounted for.
A Coast Guard cutter ship, two helicopters and a fixed-wing aircraft have been dispatched from Puerto Rico for the search, Castrodad said.
CNN's Chandler Friedman contributed to this report.