Environment Canada issued a storm warning Saturday. (EC)

Environment Canada issued weather warnings across Quebec and Atlantic Canada Saturday, caused by an "intensifying low pressure system" approaching from the southwest over the Gulf of St Lawrence by Sunday morning.

The agency forecasts 15 to 30 centimetres of snow, strong winds, freezing rain and rain by Sunday morning. Storm surges and ice rafting — ice forced onshore — are also expected in some areas.

"I think the heavier snow area is going to be New Brunswick and as you move into Quebec," said Jay Scotland, CBC News Weather Specialist. "Parts of New Brunswick could be seeing upwards of 30 cm of snow."

Weather warnings are in place in New Brunswick from the Acadian Peninsula and Miramichi in the north, to Fredericton and Southern York County in the south, and all points east.

Rain in southeastern regions is forecast to change to snow later Saturday afternoon.

"What I'm concerned about is the areas that are seeing the wet snow, that are seeing the rain, we're going to see a really quick drop in temperature moving into the overnight tonight," noted Scotland. "So any of that water that doesn't find its way into your town, or your city's infrastructure and off the streets, could become locked up as ice [which] could make for some slippery conditions."

Gusty winds were expected to develop by Saturday evening and persist into Sunday morning, reducing visibility in blowing snow.

A storm surge, higher than normal tides and some ice rafting are also expected at the high tide near noon from Point Escuminac south to Cape Tormentine. Strong winds could push the ice onshore.

Precautions should be taken along the Southern Gulf of St. Lawrence and Northumberland Strait, Environment Canada said.

Nova Scotia

The forecast calls for 25 to 50 millimetres of rain, snow and freezing rain across Nova Scotia Saturday night. Precipitation started Saturday morning in some regions.

A rain and snow boundary will set up near the Nova Scotia-New Brunswick border Saturday evening, then move southeast along the Annapolis Valley to Colchester County region.

Heavy snow is expected north of the boundary with heavy rain to its south.

Most of the precipitation is expected to end over Western Nova Scotia overnight and by Sunday morning, over eastern mainland Nova Scotia.

Cape Breton may see snow all through Sunday.

A storm surge, higher than usual tides, is also expected, particularly on the Atlantic coast of Eastern Nova Scotia and Cape Breton near midnight, Environment Canada said.

Strong winds may also drive ice onshore along north facing coastlines near noon on Sunday.

P.E.I.

The Island will also see 15 to 30 cm of snow, blowing snow, freezing rain and strong winds by Saturday night. Light rain or snow is expected throughout the afternoon. Rain, snow and freezing rain is expected tonight.

"This evening the transition from rain back to snow could see some freezing rain in between while Mother Nature makes up her mind what she wants to throw your way," said Scotland.

A rain-snow boundary will form over the western part of the Island, moving slowly towards the southeast tonight. Heavy snow can be expected north of the boundary with rain to its south.

A mix of snow and rain is expected along the boundary combined with an extended period of freezing rain, which could lead to significant icing.

Precipitation should taper to flurries Sunday morning. A storm surge and large tides are also expected. The north coast may see ice driven onto the shore.