Potential for coldest air of the season ahead. Here's when
Tuesday, January 2, 2018, 4:01 PM - 2017 ended on a record-breaking cold note, and while hopes may be high for the start of the new year, temperatures won't be, as another round of bone-chilling Arctic air is set to sweep through eastern Canada in the first week of 2018.
After a brief respite from the worst of the cold through the early part of the week, a vigorous system moving up into Atlantic Canada, combined with a building ridge in the west, will allow another - potentially even colder - shot of Arctic air to rush into eastern Canada by the end of the week. In fact, there is a chance that Ontario may see the coldest air of the season so far, with highs struggling to reach -18oC in the GTA on Friday and Saturday.
LOOKING AHEAD: Check back on January 3 for a look ahead at what we can expect for the first month of 2018 and beyond. Will the polar vortex continue to dominate or will we see an extended January thaw?
- Extreme cold warnings returned Tuesday afternoon for southwestern Ontario, from Windsor to Grey and as far east as Waterloo, after a quick break
- Mildest day is expected to be Wednesday for Ontario, Thursday for Atlantic Canada
- A powerful low pressure system moving up the east coast of the U.S. moves into Atlantic Canada late Thursday
- As this system moves into the Maritimes, cold air surges down behind it with strong winds from the north, bringing the chill back to Ontario and Quebec
- Cold air returns to the western Maritimes overnight Friday in the wake of this powerful system
- Ontario in line for coldest air of the season so far, with Friday the coldest day
While it's hard to call minus 8oC a 'warm up' for Toronto considering the average high is closer to 0oC, it should feel like a welcome relief from the minus 15oC highs of New Year's Eve. And for Montreal, the jump from minus 20oC to minus 9oC will at least put them within 10 degrees of seasonal.
But the break will be short-lived, as temperatures seem set to dive again late week - perhaps further than they did over New Year's - as a reinforcing shot of cold air is ushered down by the polar vortex.
To make matters worse, these temperatures will be accompanied by dangerous wind chill and lake effect snow squalls on Friday and Saturday.
Atlantic Canada may be in for a rougher go of it, however, as they get milder temperatures, but a potential beast of a storm to go with it.
Forecasters will be keeping a close eye on the development of this east coast system. At the moment, confidence is high that a system will develop, with the potential for significant rain, snow, and very high winds sweeping across the Atlantic provinces. Environment Canada has blanketed Nova Scotia, New Brunswick, and Prince Edward Island with a special weather statement in advance of the anticipated storm.
Long range model guidance indicates that, in the wake of this system, Atlantic Canada will again dip well below seasonal temperatures into the second week of the new year, but most signs are that the second half of January will see milder weather across the region.
Thumbnail courtesy: Larissa Hynek. Hagersville, ON.