Hurricane Bill lost some of its strength Saturday but whipped up dangerous rip tides as it roared past the northeastern US coastline toward far eastern Canada.
The storm, now a Category One hurricane on the Saffir-Simpson scale, was expected to pass far from the US New England coast, but the US National Hurricane Center (NHC) still warned of "extremely dangerous surf and life-threatening rip currents" from swells generated by the storm.
The first hurricane of the Atlantic storm season sparked a tropical storm warning for the upscale Massachusetts island resort of Martha's Vineyard, where US President Barack Obama and his family are heading for vacation Sunday. But only one inch (2.5 centimeters) of rain was expected to fall there.
On Sunday, the Miami-based NHC said large swells from Bill would continue to affect much of the US east coast and Canada's Atlantic Maritime provinces late Saturday and Sunday. Tropical storm warnings and hurricane watches were in effect for much of the coastline and some beaches were closed.
Bill moved past Bermuda earlier Saturday and swells there and in the Bahamas were set to gradually diminish overnight.
Bill's top winds were whizzing at 85 miles (140 kilometers) per hour about 255 miles (415 km) south-southeast of Nantucket, Massachusetts and 550 miles (880 km) south-southwest of Halifax, Nova Scotia, spinning northward at about 24 miles (39 km) per hour.
Most of the hurricane, the Center said, "should pass offshore of the coast of New England tonight, move over or near Nova Scotia on Sunday and be near Newfoundland Sunday night." It was expected to begin weakening Sunday as it moved over cooler waters.
In Canada, authorities issued tropical storm warnings for much of Nova Scotia's coast, where Bill was expected to pass close by on Sunday, while a hurricane watch was in effect for some far parts of the province and the eastern coast of Newfoundland.
Tropical storm warnings were in effect for the coast of Massachusetts from Woods Hole to Sagamore Beach, including Martha's Vineyard and Nantucket, meaning that winds of at least 40 miles (64 km) per hour could hit within the next 24-hour period.
Yacht owners battened down the hatches at Martha's Vineyard, a popular resort for the wealthy where the US first family was due to spend a week unwinding for the first time since Obama's inauguration in January.
The Obamas had originally planned to leave early Sunday for the holiday location but delayed their departure from Andrews Air Force Base just outside Washington until 1:45 pm (1845 GMT) amid the weather concerns.
The storm would be "marginal" in strength by the time it arrived along the Canadian coast, said Peter Bowyer of the Canadian Hurricane Center in Dartmouth, Nova Scotia.
"We now believe the storm will not strengthen anymore. In fact, it should weaken as it moves through our district," he said.
Meanwhile, Tropical Storm Hilda formed in the far western portion of the eastern Pacific basin on Saturday, moving westward with top winds at 40 miles (65 km) per hour but not expected to strengthen for the "next day or two," according to the NHC.
At 2100 GMT, it was located 1,930 miles (3,105 km) west-southwest of the southern tip of Mexico's Baja California peninsula and some 1,225 miles (1,970 km) east-southeast of Hilo, Hawaii.
The Atlantic hurricane season began on June 1 and ends on November 30.
Bill's progress follows one of the calmest starts to the hurricane season in a decade, which researchers for the state of Colorado attributed to the development of an El Nino effect in the Pacific.