Update: Jan. 15, 7:30 p.m.
Thane Road is closed to all but emergency access after a number of slides came down on Monday afternoon and evening. Between 1.5 and 2 feet of snow are covering the road in the avalanche area, according to the city.
Alaska Department of Transportation spokesperson Sam Dapcevich said the department sent a plow truck through to create a lane for emergency access, but the rest of the road is closed through at least Monday night.
“We don’t want our crews down there while the risk is still high and when we can’t see what’s going on up above,” Dapcevich said.
The department plans to do additional avalanche mitigation from noon to 2 p.m. on Tuesday. Thane Road’s avalanche gates will be closed during that time.
“If we feel like the risk is low enough, we would reopen the road until the mitigation work takes place,” Dapcevich said.
Original story
Juneau’s urban avalanche advisory is “high” on Monday, as a winter storm that dumped more than 20 inches of snow over the weekend is expected to continue through the evening.
The advisory says that avalanche activity is likely, with the potential for large snow slides. Avalanche country should be avoided for the next several days. But Tom Mattice, the city’s emergency programs manager, says avalanches are not likely to hit houses for now.
“It could get into the urban perimeter. We could see powder clouds come through the neighborhood, we could see a random avalanche get out,” Mattice said. “But in general, I think that we’re still safe in the urban environment.”
According to the advisory, the snowfall came with warming temperatures. That created an “upside down” snowpack, with very cold, light snow on the bottom and heavier snow on top. And that snowfall came after a cold snap that created icy crusts on the existing snowpack.
Light, cold snow typically doesn’t bond well with the existing snowpack, which means it could give way and trigger an avalanche.
“Right now, we have a couple of icy layers down deep in the snowpack — just really weak snow crystals,” Mattice said. “Now we’ve loaded them to a tremendous degree over the last couple of days. And the question is, how much can they take?”
The advisory said avalanche danger will likely decrease after the storm wraps up, and colder temperatures should help stabilize the mountain snowpack — but that people living in avalanche zones should keep checking the urban avalanche advisory web page for updates.
Katie Anastas contributed reporting.
