|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.
Blue skies, light winds and an uncharacteristically strong inversion continue to dominate our weather. Temperatures reached over 40F on some ridgetops yesterday, this is hard to believe from the single-digit cold air trapped in valley bottoms and parking lots. We got a report of a wet loose avalanche that ran in steep rocky terrain yesterday (photo below). With warm temperatures again today, these small wet loose slides, under rocks heated from the sun, are possible. If you decide to ride/ski on these steep South facing slopes, watch for surface warming in the top few inches of the snowpack and know that triggering a wet loose avalanche is possible.
Despite the ‘green light’ conditions, remember the snowpack has a poor structure on upper elevation slopes that have not avalanched and 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 warm temperatures and variability across the region, it’s not impossible. Keeping up with safe travel protocol is key (exposing one person at a time, grouping up in safe zones and having an escape route planned).
Small wet loose avalanche on South facing Tincan Proper yesterday. Likely triggered by rocks warming loose snow in very steep rocky terrain directly facing the sun. Thanks to Nick Crews for passing this on to us! Read more HERE.
Glide avalanches possible this week: Continued warm temperatures at the upper elevations may enhance ‘glide’ in the snowpack. Watch for glide cracks to open up and a few may release. This pattern is similar to last week when 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) and Southerly slopes near Johnson Pass.
STATE OF THE SNOWPACK??:
Below is a quick look at the snowpack, in terms of how much there is today compared to other years on this day. For snow depth, we are sitting at the 2nd thinnest January 10th, yet there are only data since 2004 when the sensor was installed. For SWE (Snow Water Equivalent), we are sitting at just over half of what we would normally be for this time of year. It has been 12 days since the last snowfall and it’s clear we are in need of a refresh!
It was a sunny balmy day yesterday in the high elevations – temperatures at 4,000′ were right around 40F. This is quite a contrast to the cold frosty single-digit-air trapped in the valleys. Ridgetop winds yesterday were light and variable and skies were clear.
Overnight, the upper elevation temperatures remained in the high 30’sF while valley bottoms, sitting in the cold pool, are anywhere between -5 and +15F. Temperatures should rise a few degrees during the day, similar to yesterday. Ridgetop winds are expected to be light, 5-10mph from the Northwest and skies clear.
As we keep looking into the weather model “crystal ball” for the next precipitation event, it looks like we could get some cloudy skies and flurries for the weekend.
|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