'Yo-yo kind of weather' hits southern Yukon with rain, slush and flooded streets

Winter has taken a brief holiday in southern Yukon this week, with a sudden spell of spring-like weather making for wet, slushy conditions — and setting the stage for some slippery roads when winter conditions return later this week.

In Whitehorse, the temperature shift this past weekend was dramatic — going from about -19 C on Saturday morning to about 1 C by the afternoon. The mild conditions have since continued, with Sunday seeing some light rain and a daytime high of 3 C, making it the warmest Jan. 28 on record.

Monday was another record-breaker, with more light rain and a daytime high of 4 C.

It's made a mess of city streets, with drivers navigating through mounds of slippery slush and vast puddles. On Monday, city crews even partially closed a portion of Second Avenue downtown to try to deal with potholes and pooling water.

"It's causing a lot of water issues," said Oshea Jephson, a spokeperson for the City of Whitehorse.

"During the summer, we can handle water because everything's draining properly, but because we're getting into the peak of winter here everything is frozen so the draining isn't happening."

Jephson said crews were going around with a steam truck to try to clear frozen drains and get water off the roads and sidewalks.

They're trying to work as fast as possible, because the mild conditions are not expected to last. The temperature is expected to be back below zero by Tuesday afternoon, and could be around -30 C before the weekend.

The concern is that any water still on the streets will turn to potentially treacherous ice when the temperature drops again.

Jephson's asking drivers to be patient and as city work crews do their best to clear the roads.  

"The sooner we can get those main arterial roadways draining properly, getting a lot of that standing water off of the road, the safer it's going to be for everyone," Jephson said.

The sudden melt over the last couple of days also poses potential problems for homeowners who are vulnerable to flooding, says Julia Duchesne, with Yukon's Department of Community Services.

"The big thing is to clear snow away from your foundations before it can melt ... that's like a pretty important step so that it doesn't leak right through to your foundation," she said.

"I'm sure people have been taken a bit by surprise, but even a little bit of snow clearing can help."

'Almost tropical'

David Phillips, senior climatologist with Environment Canada, calls the dramatic shift in weather conditions in southern Yukon over the last few days "one of the strangest bouts of weather" he's seen in his decades-long career.

"It's almost tropical. I mean these temperatures are something you might see in April, not in the dead of winter, in January," he said.

What's also notable, Phillips said, is how wildly different the temperature's been in different parts of the territory. For example, while Whitehorse and Carmacks, Yukon, were hovering a few degrees above zero on Sunday, Dawson City, Yukon — just a few hours up the highway — was nearly 30 degrees colder, at around -25 C.  

"If you want to sort of tap into the all kinds of weather, you can sometimes see all of that in one day if you cross the Yukon," he said.

Phillips says the mild conditions in southern Yukon are the result of an "atmospheric river flow" from southern B.C. and the Pacific, and the sudden temperature swing points to "Arctic air and tropical air duking it out." 

"So you get that warm air above and cold air below, and as that air kind of ebbs and flows, well, you can go from really cold conditions to mild conditions — and the contrast is quite, quite dramatic."

Phillips said even though southern Yukon is expected to return to more typical winter conditions in the coming days, the next month or two could see more ups and downs.

"The El Niño has not gone away. It's still a force," he said, referring to the natural weather pattern that starts in the tropics, and often brings warm and sometimes extreme weather. 

"My sense is that it's going to be with us really through the rest of the winter and providing this kind of a warm spell and then cold, because it goes away and then comes back. It's this kind of back-and-forth, up-and-down kind of yo-yo kind of weather."