Canadian officials are urging those in the path of Hurricane Sandy to be ready for at least 72 hours without power, while forecasters warn that some areas of the country could see in excess of 50 millimetres of rain and winds climbing up 100 km/h or more.

The storm, moving up the U.S. Eastern Seaboard, has already caused the cancellation of hundreds of flights to and from Eastern Canada.

Wind warnings were posted by Environment Canada covering much of southern Ontario, along with parts of Eastern Ontario and western Quebec along the St. Lawrence River.

"Southern Ontario, southern Quebec and southwestern Maritimes will experience high wind gusts and periods of heavy rain beginning later today and continuing into Tuesday," Environment Canada said in a bulletin issued early Monday.

Heavy rainfall is expected as early as Monday afternoon in Ontario, Monday evening in Quebec and Tuesday morning in the Maritimes. Rainfall is expected to vary between 20 and 50 millimetres depending on the area.

The Canadian Hurricane Centre says parts of southern Ontario should brace for 90 km/h winds or higher, especially along western Lake Ontario, the Niagara escarpment, Lake Huron and Georgian Bay.

CBC meteorologist Jay Scotland said the southern shores of the Great Lakes will see the risk of pounding waves and some shoreline flooding.

"If you're in the Niagara Region [or] if you're south of [Lake] Huron towards Sarnia, northerly winds will be piling that water up on shore," Scotland said. "Avoid being near the shore. The waves are fun to look at, but you'll be doing a dangerous thing to take in those sights."

Environment Canada said strong winds with gusts exceeding 90 km/h could also batter parts of Quebec.

"The chances of the gusts in the 60 to 90 km/h range are greatest in the evening and overnight," said Environment Canada meteorologist Etienne Gregoire.

"Typically, when you get in that range, you see branches broken off. With trees having a fair amount of leaves and the ground relatively wet ... it's not impossible to see trees broken off and uprooted."

Gusts up to 80 km/h are expected along coastal areas of southwestern Nova Scotia, with slightly lower winds expected farther to the north and east, the weather agency said. The Maritimes will also experience some rainfall and strong winds, as well as large waves and pounding surf.

"We have forecast offshore winds to reach probably 120 km/h… and seas will be building west of Nova Scotia, in the Gulf of Maine and at the mouth also of the Bay of Fundy," said forecaster Jean-Marc Couturier at the Canadian Hurricane Centre.

"We would be expecting probably wave heights to reach five [to] six metres in that area."

Southwestern New Brunswick should expect up to 40 mms of rain tomorrow and up to 80 mm over the next couple of days, Couturier said.

Emergency stockpile

The Canadian Red Cross issued a statement Sunday urging people to prepare for the storm by stocking a number of supplies including water, food, flashlights and a first aid kit. Hurricane Sandy could down trees and power lines and cause flooding, the organization said.

"Be prepared to take care of yourself and your family for at least 72 hours in an emergency," Mike Morton, the Canadian Red Cross director of disaster management in Ontario, said in a release. "By taking some time now to store emergency food, water and other supplies, you can provide for your entire family during a power outage or evacuation."

Among items to consider for an emergency kit are:

  • Four litres of water per person for each day of a 72-hour period (two litres for drinking, and two litres for washing)
  • Enough non-perishable or canned food for each person for 72 hours, as well as enough food for pets
  • A manual can opener
  • A crank or battery-operated flashlight, with extra batteries
  • A crank or battery-operated radio, with extra batteries
  • Spare keys for the house and car
  • A first aid kit
  • Cash in small bills, in case power outages restrict the use of bank machines
  • Other special needs items such as medications, baby formula, diapers and equipment for people with disabilities

People living in the affected areas are also being reminded to store anything outside their home that could become airborne.

"Our primary goal at this point is to make sure that everybody understands that this is going to be a serious storm and that they have a part to play, so they need to be thinking about making sure that anything that's outside is secured or taken in," said Allison Stuart, the chief of Emergency Management Ontario.

Air Canada, WestJet and Porter Airlines have all issued statements warning that flights to and from the U.S. northeast have been or will likely be cancelled in the coming days. Passengers are advised to checked the status of all flights.

More than 300 flight cancellations were posted on the website for Toronto's Pearson International Airport by mid-morning Monday.

Hurricane Sandy is currently on a northeast track off the coast of the U.S. but is projected to slam into the New York and New Jersey area before affecting Ontario, Quebec, New Brunswick and Nova Scotia.Hurricane Sandy is currently on a northeast track off the coast of the U.S. but is projected to slam into the New York and New Jersey area before affecting Ontario, Quebec, New Brunswick and Nova Scotia. (Environment Canada)