TORONTO - An approaching weather system could result in setbacks to restore power to some of the hardest-hit areas in Ontario a day after the province was blasted by gale-force winds, the province's largest electrical utility said Monday.
  
About 235,000 homes and businesses were plunged into darkness on Sunday when damaging winds of up to 100 kilometres per hour snapped trees and hydro poles and downed power lines, Hydro One said.

As of Monday evening, the number of customers still without power had been reduced to 70,000.

"Things are going in the right direction," said utility spokeswoman Daniele Gauvin.

"There are so many hundreds of trees and hundreds of lines that are down and broken poles. It's a massive restoration effort right now."

About 1,300 foresters, line maintainers, technicians and support staff from Hydro One and 22 local utilities from across Ontario were assisted by 10 helicopters as crews fanned out across the province Monday to help with restoration efforts.

"That will help us get some of the still hard hit areas . . . online hopefully within 48 hours at the latest," Gauvin said.

However, the utility said that customers in more remote locations, such as those located on islands, could be without power until Thursday or Friday.

More than half of those still without electricity are located in the Bancroft region, east of Toronto, and in Bracebridge, Huntsville and Parry Sound in the heart of southern Ontario's cottage country.

While also seeking out additional help from other local utilities and contractors, Hydro One was keeping one eye on the weather forecast for Monday night, which was expected to complicate restoration efforts.

Another approaching cold front prompted Environment Canada to issue a wind warning for regions along the eastern shores of Lakes Superior and Huron and Georgian Bay.

Winds gusting to between 60 and 80 kilometres an hour were to be accompanied by five to 10 centimetres of snow in those areas.

"If (the winds) go to a certain level tomorrow morning, we'll have to wait to see if the helicopters can fly," Gauvin said.

Conditions were forecast to start improving by Tuesday morning.

Gauvin wasn't aware of any communities that have opened emergency shelters in anticipation of a second straight night without power, but notes those decisions rest at the local level.

"Certainly the mayors of all the towns are in touch with government and in touch with Hydro One contacts," she said.

"They're aware of what's coming up next and they're making appropriate plans for each individual municipality in the province."