Spokesman Bob Robichaud said while rainfall amounts are still hard to predict, southern and eastern Ontario could see between 50 and 100 millimetres late Monday and early Tuesday.
"That's certainly in the realm of possibility for that part of Ontario," said Robichaud in an interview on Saturday. "It looks like southeastern and eastern Ontario might be getting the most rainfall out of this."
Robichaud said those areas will also see high winds, although they will likely not hit hurricane strength. He said 80 km/h winds are a possibility.
Sandy is currently moving northward over the Bahamas and is expected to continue to track north while maintaining its hurricane strength.
The latest computer models predict its effects will be far-reaching on Canadian territory, with rainy and blustery conditions also expected for Quebec and the Maritime provinces.
Western Nova Scotia will likely see the strongest winds of eastern Canada, said Robichaud.
"I don't think we'll necessarily get up close to the point where we'll have to issue warnings, but we could see some pretty blustery conditions," he said.
Typically, large hurricanes like Sandy have been known to race up the coast and clip the edges of the Maritimes and Newfoundland. But a large, high-pressure system over the Maritimes is expected to block Sandy's advance, pushing it into the mid-Atlantic states on late Monday or early Tuesday. The storm is also being fed by a trough of low pressure in the U.S. Midwest.
Robichaud said the complex interaction between these weather systems makes it difficult to predict the progress of the storm.
Sandy has so far killed more than 40 people in the Caribbean, wrecked homes and knocked down trees and power lines. Forecasters south of the border are warning the storm may cause serious damage on the U.S. eastern seaboard.
Robichaud said Sandy is headed for a densely populated zone, likely just south of the New York and New Jersey border.
But Robichaud said Canada shouldn't be bracing for the same sort of danger.
"We're not going to be feel the same impacts that they're feeling down in the U.S., that's for sure."
The Canadian government issued a news release Saturday saying it has received no reports of Canadians being killed or injured as a result of Sandy.
The storm is comparable in size to the so-called "Perfect Storm" of 1991, which remained off the coast of New England, pushing huge waves and causing $200 million in damage.
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