Winter storm watches are in effect across Nova Scotia as confidence grows in a high-impact nor’easter hitting the region this week.
Disruptive impacts from heavy snow and blustery winds are likely to affect Atlantic Canada late Tuesday into the day Wednesday. Significant snowfall totals are possible in spots, with the potential for blizzard-like conditions at times due to reduced visibility.
Some uncertainty remains in the ultimate track of the storm, which would affect precisely where the heaviest snow would fall. Folks around Halifax, Sydney, and St. John's should be on alert for impactful snowfall from this system.
Prepare to adjust travel plans through the middle of the week. Take advantage of Monday’s calm weather to make any last-minute preparations you may need before the storm arrives.
EXPLAINER: What is a nor'easter, exactly?
Budding system gathers steam south of the border
A low-pressure system that developed over the southern United States this weekend brought heavy snow to the central Plains and powerful thunderstorms to portions of the Deep South.
This system will track up the Appalachian Mountains through Monday into Tuesday, encountering a slug of cold air by the time it arrives in the Northeast.
A swath of significant snow is likely across the Northeast from northern Pennsylvania east through Massachusetts, including the Boston metro area. Up to a foot of snow could fall around these areas, so travel delays and cancellations are likely throughout the Northeast on Tuesday.
Our storm will continue strengthening as it tracks toward Atlantic Canada on Tuesday. Favourable upper-level winds and the warm waters of the Gulf Stream could allow the storm’s pressure to drop fast enough to qualify for bombogenesis, qualifying the system as a weather bomb.
This period of rapid strengthening is important because it allows low-pressure systems to produce fiercer wind gusts and heavier precipitation, making them more impactful for communities in the path of the storm.
A strong low-pressure system taking this track toward Atlantic Canada also meets the definition of a classic nor’easter, named for the powerful northeasterly winds that hammer coastal communities.
Winter storm watches issued in Nova Scotia
Environment and Climate Change Canada (ECCC) issued winter storm watches for Nova Scotia ahead of the storm’s expected arrival late Tuesday.
“Rapidly accumulating snow could make travel difficult over some locations,” the agency said in its watch on Monday morning, which covers the entirety of the province.
A track south of the Maritimes ensures this system’s precipitation will remain all snow and cold temperatures. Conditions will begin to deteriorate Tuesday afternoon as the snow begins to arrive in Nova Scotia, with heavy snow spreading across the province into Tuesday evening. Peak snowfall rates won't be until Tuesday evening and into the overnight, but luckily the heaviest snow will be done by Wednesday morning.
Winds will be quite gusty for coastal Nova Scotia while the greatest snowfall rates occur, which will drastically reduce visibility. 50-70 km/h gusts are expected Tuesday evening through Wednesday morning.
Heavy snowfall, blowing snow, and reduced visibility are all hazards with this nor’easter. All this snow is expected just a week after the historic blizzard that buried Cape Breton, leaving residents wondering where all the snow is going to go, and when is it going to melt!
The heaviest snow in the Maritimes will fall in southern Nova Scotia, Cape Breton, and eastern P.E.I., with 20-35 cm of snow expected for Cape Breton as well as 15-25 cm for Halifax, Yarmouth, and New Glasgow.
As conditions improve for Nova Scotia, Newfoundland will start to see deteriorating conditioning Tuesday overnight. The Avalon, the Burin, and the Connaigre Peninsula will see their peak snowfall rates Wednesday morning and afternoon, with northern and central Newfoundland through the afternoon and lingering into Wednesday overnight.
The snow will continue to linger on Thursday for the northern half of Newfoundland, just adding even more snow to the heavy accumulations from Wednesday.
As the low tracks close to the Avalon, some warmer air will be able to move in, bringing some mixing and even rain Wednesday afternoon and evening, slightly limiting snowfall totals, albeit the snow totals will still be high with this event.
30-50 cm is possible for the northern half of Newfoundland and along the Trans-Canada Highway. The snowfall forecast for St. John’s will be a little more tough as there is the risk for some mixed precipitation to move into the area.
Make sure to keep checking back to The Weather Network for forecast updates and impact information across the Atlantic provinces.