Hurricane Bill, the first hurricane of the 2009 Atlantic season, gained strength quickly as it churned across open ocean yesterday in the direction of Bermuda, the US National Hurricane Centre said.
Two other tropical cyclones, Ana and Claudette, were fading; Ana in the Caribbean Sea just south of Puerto Rico, and Claudette in the southern United States after slogging ashore on the Florida panhandle.
Bill's top winds reached 145 kilometres per hour, just below Category 2 on the Saffir-Simpson scale of hurricane intensity, the Miami-based hurricane centre said. Forecasters expected it to hit Category 3, with winds of more than 177 kph by today or tomorrow.
Category 3, 4 and 5 storms are considered "major" hurricanes, the most destructive type.
Bill was about 1,740 kilometres east of the Lesser Antilles at 11 a.m. EDT (1500 GMT) and was charging to the west-northwest at 16 mph (26 kph), the hurricane centre said.
On its most likely track, Bill would move well north of the northernmost Caribbean islands towards the US East Coast, forecasters said. The hurricane centre's long-range track showed it southwest of Bermuda by Saturday morning.
Tropical Storm Claudette hit the US Gulf of Mexico coast near Fort Walton Beach in the Florida panhandle early yesterday and quickly weakened to a tropical depression as it moved over southern Alabama.
Florida emergency managers reported sporadic power outages but no widespread damage. They cautioned residents to watch for rising rivers and flooding in low-lying areas.
Claudette, which sprouted with surprising speed on Sunday in the eastern Gulf of Mexico, missed the largest concentration of US oil and gas production platforms, which stretch along the coast from Mobile Bay, Alabama, to Brownsville, Texas.
The Gulf is home to almost half of US refinery capacity, a quarter of oil production and 15 per cent of natural gas output.
Tropical Depression Ana doused Puerto Rico with heavy rain yesterday as it charged through the Caribbean Sea to the west-northwest at a brisk 28 mph, the hurricane centre said.
It was located about 120 kilometres south of San Juan Puerto Rico and had top winds of 56 kph, forecasters said.