Historic Juneau Avalanches Possible
Sat, Feb. 27 – Juneau’s urban avalanche forecast is for “extreme” Juneau avalanche danger as of Saturday evening. There is a potential for “historic avalanches” in residential areas. City officials recommend that residents in the avalanche zone in downtown Juneau evacuate their homes.
The advisory also recommends that residents avoid avalanche paths including the Flume Trail. “People need to make their own safety decisions,” it stated. “But we feel that with the forecast for the next 24 – 48 hours natural avalanches are likely and of great size.”
The city and the Red Cross will open Centennial Hall as an emergency shelter. The doors opened at 8:00 p.m. on Saturday. COVID-19 mitigation measures are in place.
Juneau Avalanche Warnings were issued Friday
Juneau city officials said on Friday that there is a potential for “historic avalanches”. Depending on temperatures and how much snow falls, the city’s Urban Avalanche Advisory could be raised to an “extreme” Juneau avalanche danger, which is the highest level on the scale.
“I have never forecasted an extreme avalanche condition,” said Tom Mattice, the city’s emergency programs manager. He advised residents to be cautious, especially near the Behrends Avenue avalanche path.
Mattice says they’ve recently seen avalanches of snow four to six feet deep throughout the region. “In the urban environment, if we have a four foot deep avalanche that’s wide enough across the face of the Behrends path, (then) that’s more than enough to hit houses,” he said.
Widespread Activity and increased hazards
The Alaska Department of Transportation & Public Facilities has warned of increased avalanche hazard along Thane Road. Residents along the road should be prepared for an extended road closure if crews are unable to safely remove any avalanche debris.
The Coastal Alaska Avalanche Center says they’ve already seen widespread avalanche activity all around Juneau. They expect more avalanches over the weekend.
A freezing rain crust has formed on top of recent snow that fell on a weak snow layer. The snow’s weakness can even be triggered from a flat spot. “And then, it’ll travel through that freezing rain crust and collapse the looser snow below and the denser snow above. So it can travel great distances. We’ve already seen avalanches that have traveled over a quarter mile just from propagating through the snowpack.”
They’re warning people heading out to the backcountry to use extreme caution. Even in terrain that is generally considered safe from any avalanches.
He says the unstable snowpack conditions could potentially last through the rest of the season.