We are still waiting for significant snow to arrive here in Central Idaho. As heavy snows hit other locations around the west there have been two new accidents of note. One is the first avalanche fatality in North America. Check out: http://www.avalanche.org and click on accidents. Both accidents were human triggered in shallow snowpacks failing on a weak layer of facets (sugar snow).

We are getting reports of natural and human caused avalanches throughout our forecast area. If you are out in the backcountry and observe natural activity please email us an observation or call 208-634-0465.

There was a report from a backcountry skier that was touring within the Brundage Ski Area Boundary that set off a slide in the trees between Main Street and North.

Payette Powder Guides also reported widespread natural activity in the Lake Fork Drainage with several slides on the road cuts while driving in yesterday.

Please pay attention to the signs of instability. Recent avalanches, cracking and collapsing are Mother Nature’s warning signs. Excellent terrain and snow stability evaluation skills and conservative decision-making are essential for safe travel in avalanche terrain, especially with the unusual snowpack that we have right now.

While touring in the Fall Cr. area, snow pack is getting very warm, trees where releasing snow, small crust is starting to form on sunny aspects. 12-15cm of facets near the ground was causing Whoomping, mostly in flat areas. No other releases were observed. Snowpack was to shallow to ski (24-30 inches), mainly stayed on road going up and down.

[...] now, the snow condition experts have an additional concern. All this inviting, friendly looking snow has been subject to extreme [...]

There was an avalanche fatality down south at Rock Lake near Cascade yesterday. Two snowmobilers were caught and one was killed. The Payette Avalanche Center is investigating the slide today. PAC will also be issuing an avalanche advisory tomorrow morning. More details will be released as soon as the Sheriff’s Office concludes their investigation. This is the news report of the avalanche: http://www.ktvb.com/news/Snowmobiler-killed-in-avalanche-near-Cascade-79576732.html

The Brundage Patrol also had massive results yesterday with their explosives in the chutes above Hidden Valley. After explosives work there was still widespread failure in the snowpack with hazardous travel conditions on the ridgetop.

Be safe out there, make sure that everyone in your party is carrying avalanche gear and select your terrain wisely.

Tried to head up Jug yesterday but between the really shallow snowpack (18-30in), and experiencing several ‘whoomps’, we decided to bag it. No visible evidence of recent avys but a definite weak layer 7/8’s of the way down into the snowpack.

Toured south off Big Creek summit- 14″ new at parking. Widespread whomping, settling, and cracking on NE to NW aspects, mostly on 35 degres and less.

Still finding some whoomphing out there, toured up by Boulder peak and found some good skiing and trekking on low angle. Didn’t touch the steeps.

Yesterday on big Creek Summit, quik pit showed moderate compression results (11) with clean shear at 12″ and ~3′on due north face. Ski lines of 38 to 45 degrees, with good anchors, produced small sluffs.

On a Sunday 1/24 tour of Jug Mountain noticed supportable layers while on skis below tree line. Off skis, Boot penetration was to ground, and very faceted in shaded areas. Above tree line seem to have some consolidation from sun and warmer temperatures. 8-12 inches of new snow over surface faceting…. Sweet Turns!!

We had a very close call in the Lake Fork Drainage on Tuesday Feb 17 on a steep north facing slope near 7800 feet. A skier triggered a small slab on a slope with an average angle of 37 degrees. The skier was approximately 300 feet above another skier that had fallen on the slope below. The small slab gained in size and volume and was later classified as an R1.5,D2 avalanche based on its size and destructive force. The lower skier was almost completely buried and was able to get his hand and head out of the debris as rescuers came to his assistance. Another skier triggered a larger slab as he was skiing a lower angle slope adjacent to the first one after the rescue of his companion was completed, he rode the slab about 100 feet down the slope and was partially buried up to his waist. Neither of the skiers suffered any injuries during the experience. Two of the skiers ski cut the slope near the ridge but no further stability tests were performed before skiing the slope. Photos of the incident are available on the PAC advisory page under the advisory archive link and then by clicking on the 2/20/2010 advisory. The slab released on the new snow/old snow interface on a layer of buried surface hoar. This layer is widespread across all aspects but seems to be the most reactive on the shady aspects that did not experience the extremely warm temperatures over the weekend and into the early part of this week.

PAC has received a bunch of reports of human triggered slides over the last week. All of these slides seem to be going on the same layer of surface facets at about 35-40cm. One of these incidents was on Sargents Mt north of Brundage, one was in Lick Creek near the summit huts, and another was from Council Mt. The layer is widespread and may be preserved despite the very warm temps. We will be out looking for it in our S. Valley area today and appreciate all the great observations over the last week.

2 more slides, for our area, at Big Creek Summit on Wednesday. Skiers skied out of both slides. One occured at ~7700 on due north face. Second on an east face at ~7600. Both broke out on the very reactive surface hoar layer at 48 cm, at this location. Compression tests and extended column tests ranged between 4 and 8.