|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.
High pressure continues to dominate our weather pattern and not much is expected to change today with the exception of temperatures cooling throughout the day. The inversion is forecasted to break down as cold air pushes into the region.
It is always important to keep in mind that LOW avalanche hazard does not mean NO avalanche hazard. If heading out into the mountains today remember the snowpack has a poor structure on upper elevation slopes that have not avalanched and that were loaded by past winds (mainly North and East aspects). Hard wind slabs sit on faceted snow and/or buried surface hoar. Triggering a more dangerous slab that breaks in these layers is unlikely, however with the variability across the region, it’s not impossible. Thin rocky areas and steep convexities with poor snowpack structure are most suspect. As always practicing safe travel protocol is key (exposing one person at a time, grouping up in safe zones and having an escape route planned). Looking at potential consequences of even a small slide in complex steep terrain is an important consideration.
Buried surface hoar found in a pit on Repeat Offender yesterday. 1.10.17. This layer was not reactive but still intact.
Glide avalanches this week? Continued warm temperatures at the upper elevations over the past couple days may have enhanced ‘glide’ in the snowpack. Watch for glide cracks opening up and always avoid spending time underneath as they may release. Last week 3 glide cracks released. Known cracks exist on the South face of Eddie’s, Goldpan (behind the Magnum ridge), East face of Seattle Ridge (Northern end), Main Bowl and Southerly slopes near Johnson Pass. Anecdotally we have been observing cracks releasing as temperatures cool after a warm up. Today might be one of those days.
Glide cracks in Main Bowl. 1.10.17
Yesterday was clear, sunny and calm. The inversion was in place with ridge top temperatures above freezing and valley bottoms in the single digits. Overnight temperatures cooled slightly in the Alpine.
Today is forecasted to be similar with the exception of the inversion breaking down and cooling throughout the day into tomorrow as Arctic air moves in.
Tomorrow will be colder and clouds are actually in the forecast tomorrow night in advance of a chance of snow Friday. Fingers crossed for actual accumulation. Timing and amounts of precipitation are still TBD.
|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: Seattle Ridge
|John Sykes Forecaster
|Observation: Kickstep NE Bowl
|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