An avalanche warning is posted for one of the two mountains overlooking the city of Missoula.
"We’re seeing dangerous avalanche conditions and a snowpack that we see nowhere else in our advisory area," says Travis Craft, the director of the West Central Montana Avalanche Center which is evaluating snowpack on Missoula’s Mount Jumbo.
Mount Jumbo is the mountain with the large concrete letter “L” on its southwestern face. Officials have closed Jumbo to all public use.
Craft says his team immediately noticed unstable snowpack during their Thursday morning evaluation.
"Before we even got onto the slopes we saw an elk-triggered slide that was 75 feet across, 2.5 - 3 feet deep, and it ran about 800 vertical feet."
That slide did not reach the valley floor, but the avalanche experts — contracted by the city for $1,100 per-day they work — are watching for any potential triggers that could lead to a major slide.
"A natural trigger would be another loading event of wind and snow. An artificial trigger would include recreationalists," Craft says.
Another powerful Arctic winter storm is forecast to push into Missoula Friday evening, bringing bitter cold temperatures, powerful wind and up to 4 inches of additional snow. That’s the last thing lower Rattlesnake Valley residents living at the mountain’s base want to hear.
Thursday marked the 5-year anniversary of an avalanche on Mount Jumbo which killed one person and destroyed a home.
No evacuations are in effect yet, but area residents are strongly encouraged to stay out of their own backyards.
Nick Holloway works with Missoula’s Office of Emergency Management.
"We’re not here yet, but if there were to be an evacuation ordered, we would use Smart 911 to notify residents, as well as put out the notice through the media," Holloway says.
To sign up, visit Smart911.com
According to avalanche-expert Travis Craft, Missoula is now one of only a handful of North American cities dealing with so-called "urban avalanches".
Craft says intentionally triggering a slide on Jumbo to mitigate avalanche danger is not an option since it would risk human life and property damage.