|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.
There is an uptick in the westerly wind speeds this morning and this is supposed to continue throughout the day with gusts into the 30s at ridgelines. Since the recent snow fell over the weekend observers have been finding mostly loose soft snow that has not been acting as a slab with the exception of a shallow skier triggered soft slab on Eddies west face witnessed on Monday. As wind speeds increase it is important to remember that there is a lot of soft snow available for transport. Fresh wind slabs may form throughout the day and be sensitive to triggering. Steep, unsupported, leeward slopes will be most suspect.
Be on the lookout for wind transporting snow and pillowed or drifted areas. Avoid places where the snow feels stiffer and more affected by winds.
Skier triggered shallow wind slab on Eddies West Face. Witnessed on Monday 1.16.17
Yesterday small natural loose snow avalanches and skier triggered sluffing was observed. These were larger in Girdwood where there is more loose snow. Today in areas protected from the wind triggering a loose snow avalanche will be possible on steeper slopes. Fast moving “sluff” could entrain snow, run further than expected and easily knock you off your feet. Manage this problem by letting the snow move past you and choose terrain that doesn’t have high consequences if you fall. Although it is unlikely to bury a person, keep in mind that larger terrain will have more volume. Cold temperatures could increase this problem thoughout the week as the surface snow becomes even less cohesive.
A variety of weak layers exist with in the snowpack and vary across our region. With the exception of avalanche mitigation in Girdwood we have not been seeing avalanches breaking into old weak layers. If traveling in this part of the forecast area this is important to remember. Prior to the storm Girdwood had a shallow, weak (faceted) snowpack and now this is under 2-3 ‘ of snow. Limited snowpack information for this zone exists, triggering a deeper more high consequence avalanche is still possible. Should you see recent avalanche activity, experience shooting cracks, or “whumpfing” these are obvious clues that the snowpack is unstable.
Observers have easily been able to pick out a buried layer of surface hoar in the lower elevations below 1500’ that was buried by this last storm event. This was found to be unreactive and does not seem to pose a much of a hazard at this point but will be important to keep in mind with more snow load in the future.
If venturing into Placer or 20 Mile today remember we have very little snowpack information about both areas. We have a variety of weak layers and if you find the right spot with enough slab overlying one triggering an avalanche is still possible. It always advised to ride slopes one at a time, have a escape route planned, watch your riding partners and avoid terrain traps like steep gullies. Ease into terrain and let us know if you see an signs of instability today.
Yesterday was partly cloudy, cold and winds were calm. Temperatures were around 0F, slightly colder in the valleys and slightly warmer at ridge tops. Overnight temps were below zero and winds picked up early this morning bumping into the teens with gusts in the 20s from the W.
Single digits temperatures will continue today. Winds are forecasted to be NW 15-25 with gusts into the 30s. Skies should be mostly clear with some scattered clouds. Tonight and tomorrow will be similar. There is a chance of snow Friday into the weekend and temperatures are forecasted to rise as the deep polar air mass retreats.
|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′)
|Observation: TinCan Backdoor/ Center Ridge
|AAS L1 Turnagain
|Avalanche: Lynx Creek
|Observation: Turnagain, Seattle, Mt Ascension
|Silverton Mountain Guides
|Observation: Tincan Trees
|Dalpes/Thamm/ Schauer Forecaster
|Observation: Seward Highway across from Johnson Pass TH
|Avalanche: Base of Seattle Ridge
|Troy Tempel, Thomas Lees, .Josh Bollaert, Damian Naquin
|Observation: Lynx creek
|Observation: Tincan Trees
|Moderow / Clayton