SOMBA K'E/YELLOWKNIFE
Climatologists' predictions were right - this year has brought a truly frigid Northern winter to Yellowknife.
P. J. Menacho, left, and Bill Tetso examine the Yk Centre sign on Franklin Avenue on Jan. 30. If the sign had been functioning, it likely would have read -42 C, which was the air temperature in Yellowknife as of 10 a.m. Wednesday, according to Environment Canada. - Laura Busch/NNSL photo
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The first month of 2013 was the coldest January in the capital since 2004, with an average temperature of -28.6 C. In 2004, the mean temperature for January was -29.4 C. In comparison, the 30-year average for January temperatures is -26.8 C.
Yellowknifers really felt the cold last week, especially when air temperatures dipped below -40 C for much of the day on Jan. 30.
"You get a nice cold dome that sets up over the territories, so you need a way to punch it out," said Yvonne Bilan-Wallace, meteorologist with Environment Canada. "One way to punch it out is a lot of wind and another way to punch it out is good strong heating and a lot of sunshine – and you're not getting either one of them right now."
The dome Bilan-Wallace is referring to is a high-pressure ridge that deflects warm air from the Pacific Ocean. Because cold air is heavier than warm air, it gets trapped on the surface until strong winds or an increase in sunlight moves it.
In extremely low temperatures, extra heat is sapped from the ground but this warm air is trapped under the high pressure ridge as well, causing what weather experts call an inversion.
"It's establishing a very stable layer of air near the surface and so air that would normally rise is trapped, and if you don't have a lot of wind there is nothing to blow it away," said Bilan-Wallace.
Inversion acts somewhat like putting a lid on a pot, trapping everything underneath, she explained. Also, during cold days people tend to idle their vehicles more and more heat is radiated off of buildings, which puts more warm, moist air into the atmosphere. The result: ice fog, as was seen throughout Yellowknife on the morning of Jan. 30.
As for this month, Old Man Winter does not seem to be ready to release Yk from his grasp any time soon.
"I'm not seeing a lot of indication of big change coming in the next week or two," said Bilan-Wallace. "Even the three-month model continues to show near-normal or below-normal conditions for the NWT. So, you know, it's not a good sign right now."
A stable high-pressure ridge does not mean there will be no warmer spells, but until that ridge is broken by high winds or longer hours of sunlight, the colder air will inevitably settle back over the ground for the foreseeable future.
However, not all hope is lost, said Bilan-Wallace.
"You are on the right side of December, you are getting longer days," she said. "I mean, you're not heading into an ice age."
