|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.
A touchy snowpack was observed over the weekend as 12”-14” of new snow fell incrementally over a four-day period in Girdwood, Turnagain Pass and Summit Lake. This new snow arrived with moderate to strong Easterly ridgetop winds, which have redistributed the snow above treeline creating varying slab depths 1-2 feet thick. Several weak layers are sitting below this slab and are suspect right now in the alpine. A widespread layer of weak faceted snow remains our primary layer of concern and was the culprit in many skier triggered avalanches over the weekend. Yesterday an observation from Sunburst showed propagation potential on a layer of buried surface hoar (buried Dec.15th) which is sitting on a wind hardened bed surface along some ridgelines.
Approach your day with a cautious mind-set and be skeptical of all avalanche terrain (slopes steeper than 30 degrees) in the upper elevations. Obvious signs like cracking, wumpfing sounds, or recent avalanche activity are an immediate sign that the snow is unstable. However you may not see these signs until its too late, so remember our current poor snowpack structure is considered guilty until proven innocent. If you find yourself being tempted into bigger terrain this week keep your consiquences in mind:
A handful of human triggered avalanches occured mid-storm on Sunday 12-18 on Tincan and Eddies. Slab depths are now thicker (12-20″) since the storm subsided and triggering this layer will take more force and could break unexpectedly once onto the slope.
If headed to Summit Lake on the Kenai natural avalanche activity and skier triggered avalanches were observed over the weekend. Check out this observation from Tenderfoot where touchy wind slabs are sitting on a very thin and weak foundation. Photo of Butch Mountain (SW aspect) taken on Dec.17 by Mike Ausman.
Expect cornices to be sensitive and easy to break off. They are also likely to trigger a slab avalanche below. If you choose to walk a ridgeline today, give these a wide berth and be aware of people below you
“Sluff” may be fast moving on steep terrain features where the snow is loose and unconsolidated like in the trees. Be aware of terrain features that could have high consequence if knocked off your feet.
Snow showers yesterday brought 1-2 € of new snow throughout the day. Easterly winds were light and temperatures averaged in the low to mid 20Fs. Overnight temperature dropped into the teens and winds were calm.
Today expect mostly cloudy skies and scattered snow showers. A chance of 1-3 € of snow is possible. Winds are expected to be light and temperatures in the mid to low 20F’s.
A clearing trend is in the forecast for the next few days bringing cooler temperatures (teens and single digits F) and the possibility of gap winds for the Eastern Kenai Mountains.
|Temp Avg (F)
|Snow Depth (in)
|Center Ridge (1880′)
|Summit Lake (1400′)
|Alyeska Mid (1700′)
|Temp Avg (F)
|Wind Avg (mph)
|Wind Gust (mph)
|Seattle Ridge (2400′)
|Dalpes/Thamm/ Schauer Forecaster
|Avalanche: Base of Seattle Ridge
|Troy Tempel, Thomas Lees, .Josh Bollaert, Damian Naquin
|Observation: Lynx creek
|Observation: Tincan Trees
|Moderow / Clayton
|Observation: Turnagain (below the uptrack)
|Alaska Avalanche School Moto Level 2
|John Sykes Forecaster
|Observation: Tincan Backdoor, Center Ridge
|AAS Level 1 / R Sullivan
|Avalanche: Tincan Trees
|Schauer/ Moderow/ Stephenson Forecaster