Arthur, currently a hurricane turning northeastward along the United States coast, will approach Nova Scotia with strong winds, heavy rain and rough seas on Saturday.
Arthur will bring damaging wind gusts, heavy rain and pounding surf to Nova Scotia, Prince Edward Island and southeastern New Brunswick.
Winds will be strong enough to knock down trees, produce power outages and cause minor property damage.
Small craft are urged be in position to get to safe harbor quickly Friday afternoon and evening and to remain in port on Saturday.
The rain will be falling at a fast enough pace to cause flash flooding and could cause washouts and mudslides on secondary roads.
Showers and thunderstorms will spread northward over part of the Maritimes in the zone of warm and humid air into Friday.
Arthur will ride northeastward just ahead of an advancing cool front on Saturday.
While Arthur will undergo transformation to a non-tropical system over the cold waters of the North Atlantic, it will still be a large storm with a strong circulation.
According to Canada Weather Expert Brett Anderson, "Arthur will be a potent, fast-moving storm regardless of official classification when it hits Nova Scotia on Saturday."
The remnants of Arthur will bring locally gusty winds and drenching showers to Newfoundland and southeastern Labrador Saturday night into Sunday.
Sustained winds of 40 to 60 kph are forecast with gusts to 120 kph over Nova Scotia and across the Bay of Fundy.
"The heaviest rain will fall on the northern and western side of the storm center and is likely to fall from western Nova Scotia to Prince Edward Island and perhaps to southeastern New Brunswick," Anderson said.
Much of the 50 to 100 mm of rain forecast to fall will occur during an eight-hour period.
The storm will cause seas to rise quickly and get rough over nearby waters including the Gulf of St. Lawrence and the Bay of Fundy. Seas can reach 7 m along the southeastern coast of Nova Scotia.
"People will want to consider having batteries on hand or make sure their generator is fueled and ready to run," Anderson said.