Avalanche Warning Issued in Montana
The Gallatin National Forecast Avalanche Center has issued an Avalanche Warning for the Bridger and Northern Gallatin Ranges in Montana. Recent heavy snow has added weight and stress to a weak and unstable snowpack. The avalanche danger is rated high on all slopes throughout the range, as natural and human triggered slides are likely today. Avalanche terrain and and runout zones are should be avoided.
Avalanche Warning in the Bridger Range and Northern Gallatin Range. See today's advisory for more information. https://t.co/WHv4q93D79
— GNF Avalanche Center (@AvalancheGuys) December 2, 2016
From Tuesday, the GNF Avalanche Center showed the thin limited snow depth from the Bridger Range, which will contribute to the avalanche threat.
In a report from Thursday in the Lionhead area of West Yellowstone, the GNF Avalanche Center explained the concerns with the weak snowpack. Less snow fell around Big Sky, but wind loaded slopes facing east and south in the Northern Madison range have a considerable danger for a human triggered avalanche. This is again due to the weak and thin snowpack. A moderate risk exists in the non-wind loaded slope areas.
The Northwest Avalanche Center says their is a considerable avalanche risk in the Cascade Mountains of Washington, with a moderate risk around Mt. Hood and in the Olympic Range. The areas of biggest concern are in the back country regions, above the treeline. The forecasts do not apply for developed ski areas.
Pro Obs: Lenticulars over Baker and Colfax during another brief high pressure between storms. Yesterday's storm dropped about 35cm/+1' of dry, cold snow in Glacier Creek with a bit more near the Mt. Baker ski area environs. The new snow is generally well bonded to the old snow surface. Though we found a wind hardened layer in the middle of the new snow (from a increase in winds mid-storm) it was unreactive in stability and ski testing. Evidence of wind affect Near and Above Treeline was evident but no natural avalanche activity was observed. Of greatest note was a smattering of surface hoar in open terrain. The forecast calls for a warm up on the front end of the next system. The chance these fragile grains will survive to make for a Persistent Weak Layer is therefore low. If they do survive we could see a more sensitive snowpack over the weekend. Snow conditions were quite good also . . . Lee Lazzara – December 1, 2016 #cascadewestnorthbaker @k2_skis @outdoorresearch @julbousa @lineskis @backcountryaccess
Pro Ob. A deep day in Moonlight Bowl today (Thursday) near Stevens Pass. Average snow depth is around 100 cms. Ski penetration was in the 20cm range. The only instabilities observed were small skier triggered Loose Dry avalanches on terrain steeper than 40 degrees. Stevens Pass still has early season coverage and hazards but there is now enough snow to enjoy some backcountry skiing. Enjoy and be careful out there. Jeff Ward and Dallas Glass 12/1/16
Moderate avalanche concerns are also noted through parts of the Wasatch Range in Utah, Tetons in Wyoming, and Rockies of Colorado
A small avalanche was caught on video by a skier in Berthoud Pass, Y Chute on Hidden Knoll on the Front Range of Colorado on Tuesday.
For links to all of the avalanche centers and more forecast information, visit the American Avalanche Association at http://www.avalanche.org/
For WeatherNation: Meteorologist Mace Michaels