HALIFAX -- A winter wallop battered a wide swath of the Maritimes Friday, shutting schools, snarling traffic and making for treacherous travel.

In Halifax, a motorist who collided head-on with a snowplow shortly before 7 a.m. went to hospital with life-threatening injuries.

Halifax police said officers responded to more than 50 accidents Friday morning, as drivers attempted to negotiate steep hills and sharply curved roads in adverse conditions.

"We remind motorists to adjust their driving and be mindful of the change of road conditions throughout the day and overnight. A vehicle's stopping distance increases when it's slippery so allow extra space between your vehicle and the one ahead of you," police said in a warning.

A school bus carrying children slid sideways on an icy road in Springton, P.E.I., and became stuck at around 8 a.m., but there were no reported injuries.

Environment Canada had issued warnings and statements forNew Brunswick, Nova Scotia, Prince Edward Island.

The national weather forecaster said parts of New Brunswick were expecting up to 25 centimetres of snow before tapering off Friday night.

Snow was also expected across Nova Scotia and P.E.I., with as much as 20 centimetres expected on higher terrain such as the Cobequid Pass and the Cape Breton Highlands.

A number of schools were closed in Nova Scotia and New Brunswick ahead of the storm, and flights were cancelled or delayed at airports in Halifax, Fredericton, Moncton, N.B., and Charlottetown.

About 3,700 NB Power customers were without power by mid-morning, mostly in the northeastern corner of New Brunswick.

The storm was also forecast to hit Newfoundland late Friday and into Saturday, with as much as 20 centimetres expected.