Dec 29, 2011 @ 9:35 am

Avalanche Warning above 6000 feet

An avalanche warning has been issued for the mountains of west central Montana above 6000 feet.

Good morning, this is Steve Karkanen at the West Central Montana Avalanche Center.  At elevations above 6000 feet the avalanche danger is now HIGH.  1.5 to 2.5 inches of snow water equivalent or 10 -18 inches of snow the past 24-48 hours has been dropped onto a very weak snowpack.  Wind continues to load leeward terrain so locations that did not receive a lot of new snow will have sensitive wind slabs near ridge tops.

At elevations at or below the snow line the avalanche danger is MODERATE .

The concern we have is the very weak snowpack structure that is widespread.  We continue to see low stability scores and are able to propagate clean, energetic failures with the extended column test. The faceted layers we have been describing are now at the breaking point so it is imperative that you mitigate your risk by avoiding steep open terrain for the next few days.

All our observers will be out today checking conditions so we will have a more detailed update Friday morning.

I will issue the next update on Friday morning by 0700.   Be safe out there!


This information is the sole responsibility of the Forest Service and does not apply to operating ski areas. The avalanche danger rating expires at midnight tonight but the information can help you make a more informed decision regarding travel in avalanche terrain for the next few days.

Our advisory area includes National Forest System lands in the Bitterroot Mountains from Lost Trail Pass north to Granite Pass, the Rattlesnake Mountains north of Missoula and the Southern Swan and Mission Mountains near Seeley Lake, MT. Avalanche information for the Lookout Pass/St. Regis Basin area is available from the Idaho Panhandle Avalanche Center.