Good morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Monday, February 11 at 7:30 a.m. Pinhead Classic Telemark Festival and Moonlight Basin Ski Patrol sponsors today’s advisory. This advisory does not apply to operating ski areas.
Over the past 24 hour a trace to one inch of snow has fallen in the mountains. At 4 a.m. temperatures are in the single digits above or below zero and winds are blowing 10-20 out of the west. Today, clear skies and abundant sunshine will allow temperatures to warm into the upper teens to low twenties F and winds will remain out of the west at 10-20 mph. The building ridge of high pressure will begin to break down tonight increasing the chance of cloudy skies and light precipitation by tomorrow.
Northern Gallatin Range Northern Madison Range
On Saturday a skier triggered and was caught in an avalanche on a north facing slope near Alex Lowe Peak in the northern Gallatin Range. The caught individual lost a ski but was uninjured. The incident occurred around 6 pm on Saturday evening and both the caught skier and his partner ended up spending the night on the mountain side. Fortunately, they made it out safely on Sunday morning with the help of Gallatin County Search and Rescue.
It was reported that the avalanche broke an estimated 300 feet wide and ran approximately 500 vertical. The skier triggered the slide near exposed rocks where the snowpack was thin. A pencil hard wind slab resting over facets was the set up that produced the avalanche. A report on this incident will be available in the next day or two.
Since Saturday, a foot of fresh snow has fallen in the northern Gallatin Range. This has put additional stress on buried weak layers in the snowpack. A similar situation exists in the mountains around Big Sky. Yesterday, a skier remotely triggered a slide on a west facing slope in Beehive Basin – bull’s eye data the snowpack is unstable. The tricky part about this situation is some slopes have buried weak layers while others do not (video). There is little consistency as to what slopes harbor buried facets, so careful snowpack evaluation is essential before committing to avalanche terrain.
A more recognizable avalanche problem is wind loaded slopes. Yesterday, strong winds from the NNW loaded leeward slopes and cross loaded exposed terrain features. Both the Big Sky and Moonlight Basin Ski Patrols triggered sensitive wind slabs during control work. Wind loaded slopes will remain sensitive to the weight of a skier or rider.
Today, human triggered avalanches are likely on wind loaded slopes and slopes steeper than 35 degrees which have a CONSIDERABLE avalanche danger. All other slopes have a MODERATE avalanche danger.
Bridger Range Southern Madison Range
Southern Gallatin RangeLionhead area near West Yellowstone
In the southern Madison Range and mountains around West Yellowstone, a layer of facets buried 1-2 feet deep remains the primary avalanche concern. On Saturday, skiers near the wilderness boundary in the Taylor Fork got unstable results during stability tests and experienced a few large collapses – both signs of instability. Although this layer is gaining strength, it continues to hold the ability to produce human triggered avalanches.
In the Bridger Range – The snowpack is deep and mostly stable near the ski area, but variable conditions exist on the west side and in the northern and southern part of the Range. Areas where the snowpack is less than a meter deep, primarily in steep rocky terrain will be the most prone to human triggered avalanches.
Today, heightened avalanche conditions exist and the avalanche danger is rated MODERATE.
Cooke City
Observations from Cooke Cite continue to indicate that green light conditions exist on most slopes. However, this not a guarantee avalanches won’t happen. Unstable snow can still be found on mid to low elevation slopes where the snowpack is shallow (video). Getting stuck or stepping off your sled and sinking to the ground are prime indicators the snowpack is weak and potentially unstable. Be cautious when riding in these areas, specifically around creek beds or steep gullies. In upper elevation terrain, there is the possibility skier or rider could trigger an isolated wind slab.
Today, generally safe avalanche conditions exist and the avalanche danger is rated LOW.
Doug will issue the next advisory tomorrow morning at 7:30 a.m. If you have any snowpack or avalanche observations drop us a line at mtavalanche@gmail.com or call us at 587-6984.
February 16: 11th Annual King and Queen of the Ridge
The Avalanche Center, Montana Ale Works and Beartooth Powder Guides have already entered as teams. Organize your own team or come out as an individual hiker. Better yet, let others do the hiking for you and donate instead! If you would like to donate to the Avalanche Center team of Mark and Eric (30 lap goal!) drop us a line at mtavalanche@gmail.com. Pledges can be made per lap or just a flat donation. Kids and families are encouraged to hike too! Prizes will be awarded to the most hikes (1st, 2nd, and 3rd); most money raised; most laps for a team; most money raised for a team. More Information / Registration Form
Ice Creek Lodge in Valhallas (Canada) available at a deep discount!
Funds benefit the Friends of the Avalanche Center. Dates are March 22-29, 2013. This backcountry touring lodge is a Helicopter ride in and holds up to 10 people. The lodge is private, has full kitchen, sauna, etc., and will be a world class March trip into the Valhalla's! http://www.icecreeklodge.com/back_country_lodge_accommodation.html
Interested? Contact Eric Ladd at 406-570-0639 or eric@theoutlawpartners.com