Avalanches force highway closures

There have been at least three minor avalanches in and around the Yukon this week as temperatures rise December's heavy snowfall loosens. "(The weather) has definitely created a lot of instability in the snowpack and made the area less safe,"

“(The weather) has definitely created a lot of instability in the snowpack and made the area less safe,” said avalanche specialist Hector MacKenzie, speaking of the mountains along the South Klondike Highway toward Skagway, Alaska.

“But (avalanches) are not particularly unusual and it’s not dependent on temperature changes,” he said.

“They can happen even when it’s cold, especially with wind effect. Wind effect is a big factor for (the South Klondike area.)”

MacKenzie has been contracted to advise the Yukon’s Department of Highways and Public Works on avalanche risk. He drove down to the highway on Thursday to inspect avalanches that happened the day before.

“There are a lot of avalanches—none of them big and none of them reached the highway—that were due to rain, warm winds and also sunshine on top of fresh snow. (The snow) hadn’t had a chance to set up in any way so it was fairly unstable and it slid.”

The real danger came earlier in the week when Canadian road crews closed the highway Monday evening at around 5 p.m. in anticipation of an avalanche, said Jennifer Magnuson, communications co-ordinator for the highways department.

An avalanche did happen early the next morning, but the highway was cleaned and reopened by 11 a.m. Tuesday.

It was 1.2 metres deep, 12 metres long and approximately the width of the road, said Magnuson.

“There was some sloughs cleaned up on the highway,” she said. “They’re generally a foot deep and not that hard to clean.”

There was also a small avalanche on the Dempster (Highway) recently, said MacKenzie.

“I wouldn’t describe (any of the avalanches) as serious. They were, on a scale of one to five, they were a size one,” he said.

“Generally with warming conditions the avalanches are not so fast. Size one would probably knock someone over who was walking or skiing but wouldn’t necessarily injure them or bury them.”

Size two is definitely serious for people outside or in a vehicle, he said. (James Munson)