The Canadian Hurricane Centre in Halifax says Irene's strength is expected to diminish as it moves into the Atlantic provinces and eastern Quebec, but the storm is still expected to pack a mean punch.
The centre says it's too early to predict where the heaviest rain and strongest winds will occur because Irene's track continues to change.
However, meteorologists say the most powerful gusts are typically produced on the right side of tropical cyclones while the heaviest rain is dumped on the left side.
Environment Canada says its meteorological records show that two other powerful storms followed a path similar to Irene's predicted route.
In early September 1954, hurricane Edna caused severe damage and flooding in southeast New Brunswick when she roared through Maine and into the Maritime provinces.
Edna made landfall as a Category 1 hurricane. Sustained winds reaching 160 kilometre per hour were reported in Yarmouth, N.S. Environment Canada's website says one person died in Nova Scotia and many others were injured.
However, hurricane Gloria caused little damage in Canada when the storm took a similar route in late September 1985, prompting mass evacuations along the U.S. East Coast. Gloria made landfall in New Brunswick as a tropical storm with winds of 93 kilometres per hour, knocking out power in Fredericton and St. Stephen.
With Irene now drawing energy from the warm waters of the Gulf Stream, the storm could grow in strength in the days ahead.
Forecasters are already warning of storm surges along the Bay of Fundy, where unusually high tides are expected by midday Monday as the moon moves into a new phase.
Nova Scotia's Emergency Management Office issued a statement reminding residents that the track of the storm is only one factor to consider when preparing for rough weather."Please remember that hurricanes are very large storms and areas hundreds of kilometres outside of the track can be impacted," the office said.
"All Nova Scotians are asked to remain vigilant over the weekend and into next week. Monitor weather and hurricane forecasts. Restock 72-hour emergency kits. Review family emergency plans. Prepare your home."
Emergency kits should include adequate food and water, flashlights and batteries, crank- or solar-powered radio and copies of important documents, the agency said.
"When severe weather is imminent, outdoor items such as barbecues and lawn furniture should be tied down and vehicles should be fully fuelled."
Irene weakened slightly Friday, dropping to a Category 2 storm with maximum sustained winds near 175 km/h.
Earlier this week, Irene destroyed hundreds of homes on small islands in the Bahamas, but largely spared the capital of Nassau.
At 700 kilometres across, Irene is a huge hurricane, and a high pressure system in the western Atlantic Ocean is pushing the storm farther west than usual.
As a result, some 65 million people along the densely populated U.S. East Coast were bracing for the worst as Irene is expected to lash the cities of Washington, Baltimore, Philadelphia, New York and Boston.
Irene was expected to make landfall in North Carolina sometime Saturday.
The map below is the predicted track for Hurricane Irene: