Polar vortex tightens its icy grip, set to impact millions
Meteorologist
Thursday, February 1, 2018, 11:47 AM - An injection of warm air, but in the wrong place, has set into motion a developing frigid pattern across most of Canada for the month of February and with it, an abundance of winter weather across the south.
This bullish push of mild temperatures near Alaska acts like a surgical knife as it thrusts into the Arctic circle and cuts into the coldest air on the planet, the polar vortex, forcing this region of frigid air to settle into more southern latitudes. This type of pattern can often lead to a dominant cold snap for many areas across Canada and will be the general feature for the month ahead – but it will have starkly different impacts depending on location.
WEATHER HIGHLIGHTS:
- Polar vortex settles over Hudson Bay for much of February
- Coldest air targets northern and central Canada, with periodic shots of bitter cold air across the south
- Abundant winter weather ahead for many across southern Canada with several shots of snow
Imaged below is the warm air splitting the tropospheric polar vortex in the upper atmosphere.
Important aside: While the polar vortex is a relatively new term in the media (ever since its influence on the infamous cold snap of 2014 in North America), it is not a new term for meteorologists. The first scientific papers of a circumpolar vortex were back in the late 1940’s and early 50’s and the tropospheric polar vortex is a constant feature found both at the North and South poles.
Want to know more about the polar vortex? Watch this quick video below:
First two weeks of February
As the pattern takes shape across the country into the first full week of February, a major outbreak of Arctic air will flood in from the Prairies through Quebec as the polar vortex looms over Hudson Bay. While the polar vortex may not be directly on top of your house, the swirling airmass will act to open the flood gates to the Arctic, with frigid air freely flowing south in waves.
VIDEO: Temperature trend across Canada for the first week of February
Along the edge of the Arctic air, a hyperactive storm track develops, straddling the international border.
There will be several chances for accumulating snowfall from the B.C. mountain ranges, Alberta and into the southern Great Lakes, with messy storms across Atlantic Canada.
Going into the second week, a ridge over the Pacific Ocean will build into British Columbia and Alberta, flooding the west with milder Pacific air and re-enforcing the cold across eastern Canada. How far east that Pacific air can press is still to be determined, but it seems likely most southern Prairie communities will experience a break from the deep cold towards mid month.
Mid-February
“Heading into the middle of February, many models show a brief breakdown of the pattern with milder Pacific air flooding the southern half of the country,” says The Weather Network’s meteorologist Dr. Doug Gillham. “While this goes against our expectations based on the global pattern, this is something we will closely monitor, but we aren’t completely buying just yet.”
The reason? The global pattern makes a strong case for cold air to remain firmly entrenched over eastern Canada, with the Pacific air confined to western Canada, but models aren’t supporting this idea. However, it is not uncommon for forecast models to contradict the pattern in the long range and it is a forecaster’s role to diagnose these errors.
What does this mean for your area?
British Columbia: A fresh top off of alpine snow, but scattered and periodic rain for lower elevations for the first week of February, general drying trend (but think foggier for lower elevations) as we head into the mid-month. More information here.
Alberta: Rounds of snow in the Rockies, foothills and southern portions of the province. Colder air locked up in the northeast. Milder Pacific air flows over the Rockies into the second week of February, ending the active storm track. More information here.
Saskatchewan & Manitoba: Below seasonal temperatures persist for the first week, with temperatures trending milder towards mid month. Very few storms, primarily targeting southern Saskatchewan.
Ontario & Quebec: Storm track south of the Great Lakes will lead to several shots of snowfall over the next two weeks for southern Ontario and Quebec. Across the north, temperatures 5 to 10 degrees below seasonal, but mainly sunny.
Atlantic Canada: Changeable temperatures, with brief blasts of Arctic air as an active storm track sets up through the region, leading to messy systems and flooding concerns.
Northern Canada: Frigid temperatures and dangerous wind chills for central and northern Canada will likely persist for weeks, with a tendency for the Yukon to trend milder into the second week of February.
Make sure to check back for updates as we fine-tune the forecast.
