Strong rains and winds lashed the Atlantic Canada region as Fiona closed in early Saturday as a big, powerful post-tropical cyclone, and Canadian forecasters warned it could be one of the most severe storms in the country's history.

Fiona transformed from a hurricane into a post-tropical storm late Friday, but meteorologists cautioned that it still could have hurricane-strength winds and would bring drenching rains and huge waves.

More than 250,000 Nova Scotia Power customers - about half of all customers in the province - were affected by outages just past 1 a.m. local time. The tally rose by another 28,000 by the end of the hour.

The fast-moving Fiona was forecast to make landfall in Nova Scotia before dawn Saturday, with its power down from the Category 4 strength it had early Friday when passing by Bermuda, though officials there reported no serious damage.

The Canadian Hurricane Centre issued a hurricane watch for coastal expanses of Nova Scotia, Prince Edward Island and Newfoundland.

The U.S. National Hurricane Center said Fiona should reach the area as a "large and powerful post-tropical cyclone with hurricane-force winds."

"It's going to a bad one," said Prime Minister Justin Trudeau, who decided to delay his trip to Japan for the funeral for assassinated former Prime Minister Shinzo Abe.

"We of course hope there won't be much needed, but we feel there probably will be," Trudeau said. "Listen to the instructions of local authorities and hang in there for the next 24 hours."

The U.S. hurricane center said Fiona was at Category 2 strength late Friday, with maximum sustained winds of 105 mph (169 kph). It was centered about 140 miles (220 kilometers) southeast of Halifax, Nova Scotia, heading northeast at 46 mph (74 kph).

Hurricane-force winds extended outward up to 185 miles (300 kilometers) from the center and tropical storm-force winds extended outward up to 345 miles (555 kilometers).

"This is definitely going to be one of, if not the most powerful tropical cyclones to affect our part of the country," said Ian Hubbard, meteorologist for the Canadian Hurricane Centre in Dartmouth, Nova Scotia. "It's going to be definitely as severe and as bad as any I've seen."

Hubbard said the storm was weakening as it moved over cooler water, and he felt it highly unlikely it would reach land with hurricane strength.

Hurricanes in Canada are somewhat rare, in part because once the storms reach colder waters, they lose their main source of energy. But post-tropical cyclones still can have hurricane-strength winds, although they have a cold core and no visible eye. They also often lose their symmetric form and more resemble a comma.

"Still holding strong. But it's getting very scary," Amanda McDougall, mayor of Cape Breton Regional Municipality, told The Associated Press.

People in the area rushed to stock up essentials and worked to stormproof their properties Friday.

At Samsons Enterprises boatyard in the small Acadian community of Petit-de-Grat on Nova Scotia's Cape Breton Island, Jordan David helped his friend Kyle Boudreau tie down Boudreau's lobster boat "Bad Influence."

"All we can do is hope for the best and prepare as best we can. There's something coming, and just how bad is yet to be determined," said David, wearing his outdoor waterproof gear.

Bob Robichaud, Warning Preparedness Meteorologist for the Canadian Hurricane Centre, said Fiona was shaping up to be a bigger storm system than Hurricane Juan, which caused extensive damage to the Halifax area in 2003.

He added that Fiona is about the same size as post-tropical storm Dorian in 2019. "But it is stronger than Dorian was," he said. "It's certainly going to be an historic, extreme event for eastern Canada."

Christina Lamey, a spokesperson for the Cape Breton Regional Municipality, said the Centre 200 sports arena in Sydney was being opened Friday night to take in residents who wanted to evacuate from their homes during the storm. Halifax said it would open four evacuation centers.

Officials on Prince Edward Island sent out an emergency alert to phones warning of the potential for severe flooding on the northern shore of the province. "Immediate efforts should be taken to protect belongings. Avoid shorelines, waves are extremely dangerous. Residents in those regions should be prepared to move out if needed," the alert read.

Authorities in Nova Scotia also sent an emergency alert to phones warning of Fiona's arrival and urging people to say inside, avoid the shore, charge devices and have enough supplies for at least 72 hours. Officials warned of prolonged power outages, wind damage to trees and structures and coastal flooding and possible road washouts.

Fiona so far has been blamed for at least five deaths - two in Puerto Rico, two in the Dominican Republic and one in the French island of Guadeloupe.

Meanwhile, the National Hurricane Center said newly formed Tropical Storm Ian in the Caribbean was expected to keep strengthening and hit Cuba early Tuesday as a hurricane and then hit southern Florida early Wednesday.

It was centered about 385 miles (620 kilometers) southeast of Kingston, Jamaica. It had maximum sustained winds of 40 mph (65 kph) and was moving west-northwest at 12 mph (19 kph). A hurricane watch was issued for the Cayman Islands.