Residents in a section of downtown Juneau should evacuate due to extreme danger from potentially historic avalanches, the City and Borough of Juneau announced on Saturday.
City officials recommended that residents in the avalanche zone of the Behrends neighborhood in downtown Juneau evacuate their homes by evening.
“By mid-day tomorrow danger levels should start to subside yet CBJ will be monitoring the situation closely and sharing additional information,” the city statement said.
The city and the Red Cross are opening Centennial Hall as an emergency shelter for anyone who chooses to leave their home. The doors will open at 8:00 p.m. on Saturday and COVID-19 mitigation measures will be in place.
In the advisory, Emergency Manager Tom Mattice also recommended that all residents avoid avalanche paths including the Flume Trail.
“People need to make their own safety decisions,” he wrote. “But we feel that with the forecast for the next 24 – 48 hours natural avalanches are likely and of great size.”
Avalanche forecasters warned Friday about increasing danger in downtown Juneau and the surrounding backcountry, especially as more snow and rain fell on an already unstable snowpack. Avalanche risk categorized as “extreme” is very uncommon.
“I have never forecasted an extreme avalanche condition,” said Tom Mattice, the city’s emergency programs manager said.
Mattice said they’ve recently seen avalanches of snow 4 to 6 feet deep throughout the region.
“In the urban environment, if we have a 4-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.
The Alaska Department of Transportation & Public Facilities also 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.
Kanaan Bausler of the Coastal Alaska Avalanche Center says they’ve already seen widespread avalanche activity all around Juneau, from Douglas Island down to Snettisham Inlet.
A freezing rain crust has formed on top of recent snow that fell on a weak snow layer. Bausler says the snow’s weakness can be triggered from even a flat spot on the terrain.
“And then, it’ll travel through that freezing rain crust and collapse the looser snow below and the denser snow above,” he said. “So, it can travel great distances and we’ve already seen avalanches that have traveled over a quarter mile just from propagating through the snowpack.”
He says 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.
KTOO reporter Matt Miller and editor Jennifer Pemberton contributed to this report.
This story has been updated.