The current avalanche danger for the west central Montana backcountry is MODERATE. Human triggered avalanches are possible natural avalanches are unlikely, large avalanches may occur in isolated or wind loaded areas. This danger rating does not apply to operating ski areas, expires at midnight tonight and is the sole responsibility of the U.S. Forest Service.
Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Thursday, February 18th, 2016.
Weather and Snowpack
Temperatures have been unseasonably warm and winds have persisted over the last few days. Currently temperatures at mountain locations are just above freezing and little to no snow has accumulated overnight. Ridge top winds are 18mph and gusting to 28mph out of the SE in the Bitterroot.
Yesterday Tim and I rode up to Rocky Point and found the snow to be settling and bonding well. The primary avalanche concern that we observed were windslabs. We were able to get a propagation on a wind loaded north aspect (pit) and also saw some localized cracking on other wind loaded aspects (pic). Be suspicious of all lee terrain and carefully assess each slope. Not all windslabs we saw were reactive, but the windslabs we did see were widespread and had the potential to be large slides as well as characteristics conducive to step down to a weak interface deeper in the snowpack. Always consider the consequences of getting caught if the slope you are thinking of skiing or riding were to slide.
The snowpack varies greatly with elevation, rain fell earlier this week to around 6500ft and the lower elevations have had a few days to adjust to the rain event and are continuing to lock up. Above about 6500ft the snow is cooler and weaknesses like facets can still be found. There is a melt freeze crust with facets just below that has been observed in the advisory area at higher elevations the last few days and was the layer that we observed propagating yesterday and Travis saw Q1 shears on in the Rattlesnake on Monday. Be mindful of the changing snowpack and look for areas where facets may have formed.
Avalanche and Weather Outlook
The weather looks to be shifting towards cooler temperatures and light snowfall should be starting up by this afternoon bringing a few inches of snow to the advisory area by Friday. Colder temperatures and snow should persist into the weekend. Avalanche conditions will remain the same until the snow starts to accumulate but with new snow for transport and strong westerly winds windslabs will continue to grow in size.
The next avalanche advisory will be issued on Saturday.