|Travel Advice||Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.||Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.||Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding, and conservative decision-making essential.||Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.||Extraordinarily dangerous avalanche conditions. Avoid all avalanche terrain.|
|Likelihood of Avalanches||Natural and human-triggered avalanches unlikely.||Natural avalanches unlikely; human-triggered avalanches possible.||Natural avalanches possible; human-triggered avalanches likely.||Natural avalanches likely; human-triggered avalanches very likely.||Natural and human-triggered avalanches certain.|
|Avalanche Size and Distribution||Small avalanches in isolated areas or extreme terrain.||Small avalanches in specific areas; or large avalanches in isolated areas.||Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.||Large avalanches in many areas; or very large avalanches in specific areas.||Very large avalanches in many areas.|
Yesterday my partner and I found generally stable snow in the higher elevations. We found evidence of extensive avalanche activity that had occurred during and immediately after the most recent storm on Tuesday Dec 9th. Looking under the snow surface showed us mostly strong snow with one exception. We were able to see some propagation potential along a weak layer 18″ below the surface. Because of this result and only minimal information since the storm, it will be wise to treat steep upper elevation slopes with a healthy dose of respect. While the weak layer in question in our snowpit is one that typically stabilizes quickly, I’m not ready to jump into this type of terrain without gathering more information from below the surface. The general trend today will continue to be towards better stability. The likelihood of triggering an avalanche is on the low end of the scale, BUT there are stiff older wind slabs that are sitting on weaker snow. These older wind slabs will be difficult to recognize, as they are blanketed by low density powder.
Venturing into steeper terrain in the upper elevations will require advanced snowpack assessment skills and the ability to detect old wind slabs hiding underneath 8-10″ of light powder. You can also hedge your bets by sticking to terrain 35 degrees or less in the alpine today.
As mentioned above, early season hazards and a stout & slick rain crust in the mid elevations are legitimate concerns and require careful travel in order to avoid injury.
Yesterday we observed one glide avalanche on the East face of Pyramid that had moved 10-20 feet downhill over the past day. While glide avalanches are not a widespread issue currently, it is worth keeping them in mind. Both Eddies and Tincan have numerous older glide cracks that have not moved over the past couple of weeks. The nature of glide avalanches makes it very difficult to know when they might release. With this in mind, it is best to steer clear of glide cracks and to keep track of where they are.
Earlier this week rain, snow, warm temps and moderate winds created unstable conditions throughout the area. Since Tuesday Dec 9th, the weather has quieted down and allowed the snowpack to adjust.
Temperatures over the last 24 hours have cooled into the low 20s F. Ridgetop winds have been light and there has been no new precipitation.
Today expect a continuation of this quiet weather. Skies will be mostly clear with some fog in the valleys. Temperatures will be in the low 30s F at 1,000′ and in the mid 20s F at ridgetop levels. Winds will be light out of the North at 5-15 mph. No new precipitation will fall today.
The extended outlook is showing a chance for snow and possibly rain at the lower elevations as we head into the weekend.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||29||0||0||18|
|Summit Lake (1400′)||22||0||0||4|
|Alyeska Mid (1700′)||29||0||0||11.8|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||28||var||8||23|
|11/27/23||Turnagain||Avalanche: Tincan Ridge||Schauer/ Stiassny Forecaster|
|11/26/23||Turnagain||Observation: Road report: Slide with dirt on Repeat offender||Anonymous|
|11/26/23||Turnagain||Observation: Pete’s North||Ben Sullender|
|11/25/23||Turnagain||Observation: Tincan trees||John Sykes Forecaster|
|11/21/23||Observation: Spokane Creek||John Sykes Forecaster|
|11/19/23||Turnagain||Observation: Magnum – PMS Bowl||Schauer/ Cullen/ Jonas Forecaster|
|11/19/23||Other Regions||Observation: Sunnyside/Penguin||Jose Ramos-Leon|
|11/19/23||Turnagain||Observation: Eddies||Andy Moderow|