Tropical Storm Rafael pummels Virgin Islands, heads toward Bermuda October 14, 2012 -- Updated 1024 GMT (1824 HKT) On Bay Road in Basseterre, St. Kitts, two taxis were washed down to the shoreline when they tried to cross the flooded road. Hurricane center: Rainfall could cause "life-threatening flash floods and mudslides" The tropical storm could become a hurricane by Monday Efforts to find three passengers on a downed plane continue despite the weather (CNN) -- Tropical Storm Rafael unleashed heavy rain and powerful gusts on the Virgin Islands early Sunday and could turn into a hurricane by Monday, forecasters said. With sustained winds of 50 mph, Rafael could get even stronger as it bears down on several islands popular with tourists. As of 5 a.m. ET, Rafael was centered about 100 miles north-northwest of St. Marten, the National Hurricane Center in Miami said. The storm was moving north-northwest at 13 mph and is expected to turn northward by Monday. A projection map shows Rafael headed toward Bermuda later this week. A tropical storm warning is in effect for Anguilla. Tropical storm warnings that had been in effect for the U.S. and British Virgin Islands, St. Marten, Antigua, Barbuda, St. Kitts and Guadeloupe were discontinued Sunday morning. College Street, which runs through the middle of Basseterre, is filled with floodwaters. Basseterre flooding has cut off the east side of the city from the west side. Forecasters expect Rafael to leave between 3 to 5 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 impact rescue efforts for two men and one woman whose small aircraft crashed Saturday morning about six nautical miles (7 miles) south of St. Thomas in the U.S. Virgin Islands, Coast Guard spokesman Ricardo Castrodad said. 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. The effort continued Saturday night despite what the Coast Guard spokesman said were deteriorating conditions due to Rafael.