3rd nor'easter in 5 days to roll through Nova Scotia Tuesday

Nova Scotia is in for a mix of heavy snow, rain and wind, completing a nor'easter hat trick for the region in less than a week.

CBC meteorologist Kalin Mitchell said the snow will start in southwestern Nova Scotia and New Brunswick Tuesday morning and spread northeast across the Maritimes Tuesday afternoon and evening.

This will make for a messy evening commute on Tuesday for most Nova Scotians as the snow begins to accumulate.

"Prepare for quickly changing and deteriorating travel conditions," said Environment Canada. "Take extra care when walking or driving in affected areas."

Winter warnings, watches and statements

The system has prompted Environment Canada to issue weather watches and warnings for the province.

Mitchell expects to see up to 25 centimetres of snow in southwestern parts of the province, the Annapolis Valley and parts of Cumberland County, along with higher elevations in Cape Breton. He says people along the Atlantic coastline and into northern Nova Scotia can expect eight to 15 centimetres of snow.  

Even more snow is possible Tuesday evening and Environment Canada has issued winter storm warnings for the following counties:

• Annapolis County.
• Digby County.
• Lunenburg County.
• Queens County.
• Shelburne County.
• Yarmouth County.

It's in these counties that strong east to northeasterly winds will develop. They are expected to gust to 90 km/h to 110 km/h during the day and evening.

The rest of the province remains under a winter storm watch with up to 15 centimetres expected to begin falling late in the day before changing over to rain. Winds are expected to gust in these areas to as much as 90 km/h during the evening.

Mitchell says northern Inverness County could see winds gusting as high as 130 km/h.

With wind conditions like these, there's a higher risk of power outages.

As a result, Nova Scotia Power says it's stationing power line crews and forestry teams across the province as it activates its emergency operations centre ahead of the storm.

Besides the windy conditions, pounding surf is expected along the Atlantic coastline. Environment Canada issued storm surge warnings on Monday afternoon for Lunenburg, Queens and Shelburne counties. 

7-10 metres waves in some areas

The weather agency is also warning of damage to the coastline as the combination of low pressure and easterly winds could churn up seven- to 10-metre waves at high tide Tuesday evening in southwestern parts of the province. Along the Eastern Shore, waves could be between three and five metres high.

"There is a risk of localized flooding during these high tides as well as coastal erosion and infrastructure damage due to heavy pounding surf, especially as some of these same coastal areas were already affected by similar conditions last week," the warnings say.

The risk won't go down with the tide, either. The weather service says the "high waves will be persistent" along parts of the coast that face east and southeast and could continue for several hours after high tide.

It also warns there will be powerful surf Wednesday morning at high tide along the entire Atlantic Coast of the mainland, and possibly in southern parts of Cape Breton.  

The following counties are under a special weather statement due to the risk of higher than normal water levels:

• Guysborough County.
• Halifax County.​
• Richmond County.
• Sydney Metro and Cape Breton County.