Good Morning. This is Mark Staples with the Gallatin National Forest Avalanche Advisory issued on Friday, January 8, at 7:30 a.m. The Dance Center, in cooperation with the Friends of the Avalanche Center, sponsor today's advisory. This advisory does not apply to operating ski areas.
Today will be another beautiful day in the mountains with sunny skies and warmer temperatures than yesterday. This morning mountain temperatures were in the high teens F with valley temperatures near or below zero. This inversion was especially noticeable in West Yellowstone where valley temperatures were -32 degrees F while it was 16 degrees F near Lionhead ridge. Winds this morning were blowing 10-15 mph from the W. Under clear skies today temperatures will climb into the upper 20's F and winds will remain light at 10-15 mph. Some stronger winds are possible at lower elevations this morning as cold air mixes with warmer air.
Southwest Montana has experienced the most widespread avalanche cycle in the advisory area since the Avalanche Center began 20 years ago. Masters of the avalanche business have told me that "it looks like the continental snowpack is in full bloom" and unfortunately "the stabilization process is going to take a long time." We have many photos and videos of recent avalanches. Click on the links below, or visit the photo or video pages on our website.
Yesterday saw more avalanche activity.
- Eric and I rode in the Taylor Fork area where we observed recent avalanches everywhere.
- Doug and his partner skied in Beehive Basin where they experienced collapsing and cracking of the snowpack. Knowing they could easily trigger an avalanche, they ascended a low angle ridge and triggered a large avalanche as they descended the same ridge. See a photo and a video of this slide.
- A skier ascending a ridge on Yellow Mountain, near Big Sky, triggered another avalanche (photo) when the slope collapsed and propagated a fracture into two avalanche paths over 100 ft away from him.
- Just off Buck Ridge an experienced snowmobiler intentionally triggered an avalanche nearly 1000 ft wide (photo).
- In the backcountry on Lone Mountain, another slide was triggered even though almost 20 people skied the same slope on the previous day (photo).
Avalanches throughout the advisory area are breaking 2-3 ft deep on a layer of weak faceted snow. This layer is easy to find in snowpits and continues to produce clean shears in stability tests with low scores. Natural avalanche activity is diminishing, but the snowpack is close enough to its breaking point that the weight of a skier or rider will be enough to tip the balance and trigger an avalanche.
What to do? Today will be a great day to be in the mountains with sunshine and plentiful powder. Yesterday, Eric and I had a great day choking on powder as we rode in the Taylor Fork area where we didn't go anywhere near avalanche terrain which included low angle slopes connected to steeper ones. We were mindful that the combination of sunshine and deep powder euphoria sometimes causes a false sense of confidence in the snowpack. As we have seen on Lone Mountain and Scotch Bonnet, avalanches sometimes occur after many people have been on a slope. The snowpack remains very sensitive especially in isolated areas where downhill winds loaded slopes with wind drifted snow well below ridgetops. These drifts may not be obvious but could be deadly. I would seek low angle meadows today and avoid steep slopes like ones on Saddle Peak. Today throughout the advisory area, human triggered avalanches are probable and the avalanche danger is rated CONSIDERABLE.
Eric will issue the next advisory tomorrow morning at 7:30 a.m. If you get out in the backcountry give us a call or email with your observations. You can reach us at 587-6984 or email us at mtavalanche@gmail.com.