Parts of Nova Scotia and Newfoundland are facing upgraded weather warnings as an Alberta clipper system heads east.
Environment Canada has updated the weather warning for the eastern parts of both Nova Scotia and Newfoundland to a yellow warning, meaning they expect to see immediate and localized impacts of severe weather.
“We’ve got a variety of warnings,” Ian Hubbard, meteorologist with Environment and Climate Canada said in an interview Monday. “We’ve got a winter storm warning for some regions, we’ve got wind warnings in effect, and we also have snow squall watches for some areas.”
An “Alberta clipper” refers to a fast-moving weather system that generally originates in the Rockies and swoops south and east across the Great Plains, bringing gusts of cool, dry winds.
In Nova Scotia’s Cape Breton and Pictou County, the weather agency is warning that the combination of up to 20 centimetres of falling snow and 70-kilometre per hour wind gusts could result in snow squalls.
While a blowing snow warning typically deals only with snow that’s already on the ground or is falling, Hubbard says a snow squall can create its own flurries.
When cooler wind blows over warmer water — in this case, the waters of the Gulf of St. Lawrence and the Northumberland Strait — it can generate flurries.
“When you get these strong northwesterly winds heading in the same direction over several hours, you get these bands of heavy flurries,” Hubbard said. These squalls not only reduce visibility, “but they’re actually able to dump or precipitate a lot of snow on the ground as well.”
The agency says there is a risk that visibility could suddenly reduce to zero at times, and people should be ready for quickly changing travel conditions.
Strong northwesterly winds were set to develop Monday afternoon over Cape Breton and along the Northumberland Strait, eventually moving the weather system to southern Newfoundland.
Across much of eastern Newfoundland, 10 to 20 centimetres of snow was expected beginning Monday evening and continuing to Tuesday, with winds up to 80 kilometres an hour possible. Across the Avalon Peninsula on the eastern coast, gusts could climb up to 110 kilometres an hour.
On the west coast, some areas were also under a snow squall watch as of early afternoon Monday.
“We’re looking at a bit of snow falling in the forecast. Not enough to trigger a snowfall warning, but with the snow on the ground and the strong winds, we are expecting blowing snow to be an issue there, causing some reduced visibility,” Hubbard says.
Hubbard says the agency will keep a close eye on the weather as it develops, and it’s possible the warnings could be upgraded again before the clipper system clears the area.