Winter is returning, but hopefully the recent mild and relatively warm weather over Canada's East Coast hasn't lulled people into a false sense of spring.

Environment Canada's winter storm warnings — issued when several types of severe winter weather are expected to happen together — are in place for the four Atlantic provinces and the Gaspé Peninsula. 

An alert on Environment Canada's website says to consider postponing non-essential travel until conditions improve because rapid accumulations of snow could make travel difficult in some areas. "Prepare for quickly changing and deteriorating travel conditions," it says.

An intensifying low-pressure system will move from over the Great Lakes Basin, to across the Bay of Fundy and into the Gulf of St. Lawrence. Snow, which may be heavy at times, will begin Tuesday evening, and change over to rain for some parts of the Maritimes and the Gaspé late Wednesday morning.

As the low-pressure system continues to move east on Wednesday, the rain will taper off and temperatures will drop below freezing, with flurries developing Wednesday evening, according to Environment Canada.

N.S., Cape Breton get whiteout warnings

The national weather service estimates total snowfall of 15 to 30 centimetres, with highest amounts expected over northeastern Nova Scotia and Cape Breton.

Easterly winds of between 90 and 110 km/h, combined with the heavy snow, are expected to result in whiteout conditions on Wednesday. Winds will shift to the southwest in the afternoon and gust near 80 km/h.

Areas of Nova Scotia southwest of Halifax and Hants counties are not under any warnings. 

In New Brunswick, winter storm warnings extend across most of the province, except for areas in the eastern, central part of New Brunswick, including Edmundston, Grand Falls and Woodstock. 

The rest of the province can expect total snowfall of up to 25 centimetres, with winds to 70 km/h.

A storm surge warning was in place Wednesday for New Brunswick's east coast, due to high tides.

"Additionally rough and pounding surf is expected as a result of the strong northeast winds associated with the system," according to Environment Canada, adding that coastal flooding is possible.

Prince Edward Island, under a storm warning, faces estimated total snowfall of 15 to 20 centimetres, with winds gusting to 90 km/h, which may cause dangerous driving conditions. 

Newfoundland expecting a wintry mix 

Two communities in Newfoundland are under winter storm warnings — Burgeo and Channel–Port aux Basques. About 15 centimetres of snow and high winds to 110 km/h are expected, also possibly causing treacherous driving conditions. 

Large waves and pounding surf, expected to combine with a storm surge on Wednesday afternoon and evening, may cause minor flooding and damage in southeast-facing communities near the shore during the high tides, says Environment Canada.

Most of the rest of the island of Newfoundland remains under a winter storm watch, except for the Avalon Peninsula, where a special weather statement is in effect. 

The weather for the Avalon Peninsula isn't clear, but Environment Canada says there could be ice pellets mixed with blowing snow. 

Labrador seems mostly unscathed, except for a special weather statement across that part of the province.