Flight cancellations have already started at the Halifax Stanfield International Airport as the Maritimes brace for a spring blizzard that could dump more than 30 centimetres of snow and bring wind gusts of more than 100 kilometres per hour.

Dozens of arriving and departing flights to and from Toronto, Ottawa and within the Maritimes on Wednesday have already been cancelled.

Maritime Bus, the region's interprovincial bus service, has cancelled all of its runs for Wednesday with the exception of the Halifax airport route, which is scheduled to continue.

On Tuesday afternoon, officials warned severe wind conditions throughout the day on Wednesday may also result in restrictions of traffic on the Confederation Bridge.

The nor'easter is expected to make its way up the U.S. Eastern Seaboard late Tuesday and into Wednesday. The storm is forecast to begin early Wednesday morning in southern Nova Scotia and bring whiteout conditions across the region through the day.

Forecasters say the possibility of damage is real because a storm surge will bring rising waters along the coastlines of Nova Scotia and northeastern New Brunswick — in some cases 50 to 80 centimetres higher than normal, with strong waves driving the sea into shore.

Winter storm

Whiteout conditions are expected throughout the Maritimes on Wednesday as the region braces for a spring blizzard.

"Through much of the day, the visibility is going to be the biggest concern with prolonged whiteout conditions anticipated," said CBC meteorologist Kalin Mitchell.

Mitchell said snow will begin in the mid to late morning in southern New Brunswick and in eastern P.E.I. By the afternoon, the snow will spread to all corners of both provinces, he said.

"The south and southeast of New Brunswick, as well as western P.E.I., could see snowfall accumulations of 30 to 50 centimetres," said Mitchell.

"In eastern P.E.I., some mixing in of rain is expected late in the day on Wednesday and may keep snowfall amounts slightly lower, but not by much."

A storm surge is possible around the Northumberland coastline of New Brunswick and ice may pile against the Gulf of St. Lawrence coastline on P.E.I. as well, said Mitchell.

Geoff MacLellan, Nova Scotia's Transportation and Infrastructure Renewal Minister, is warning people to use good judgment before venturing out tomorrow.

"Stay off the roads if possible but, if you must travel, check the 511 road information line for updates," said MacLellan.

"Be especially aware for possible closures in windy areas such as the Canso Causeway, the Cobequid Pass, and the Tantramar Marshes."

People are encouraged to check on those who may be vulnerable or living alone, to see if they need assistance. Pets should also be brought indoors.

The Department of Public Safety's Emergency Measures Organization in New Brunswick is encouraging residents to have emergency kits ready for their homes and cars.

Severe winter storm warnings have also forced Canadian Blood Services to cancel all blood donor clinics in New Brunswick, Nova Scotia and Prince Edward Island on Wednesday.