|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.
I think the word is out that Turnagain Pass is not the place to find powder snow – this weekend anyhow… After a very warm storm rolled through Thursday saturating much of the snowpack up to 2,500′ and the surface layers up to 3,500′, the pack is slowly freezing from the top down. The rain wiped out much of the snow below 1,500′ and hiking is required from the parking lots at the Pass. Above 1,500′, the snowpack does get deeper quickly, but it’s the surface conditions that are the challenge. In short, the surface crust is mostly supportable, hard and slick. Beware that steep slopes have a slide-for-life character.
Where the crust ends and the soft snow begins is likely around 4,000′. If you are headed to these high elevations, assessing the snowpack is key. Keep your eye out for weak snow, such as buried surface hoar or facets, sitting under stiffer slabs. Finding a slab avalanche, most likely a wind slab, in these more remote and high elevations is possible.
For more details on snowpack and surface conditions, check out the several observations sent in yesterday from a level 2 avalanche course in the neighborhood. Thanks Alaska Avalanche School!
Many glide cracks continue to open up in the forecast zone. During the day yesterday several new cracks were seen opening as well as existing cracks widen. None were reported to have avalanched but one avalanche instructor commented “We would not want to be below these glide cracks right now!”. That said, these are easy to recognize and avoidance is the best tactic considering their unpredictable nature and destructive potential. This is not the kind of avalanche a person can trigger, rather would be a case of being in the wrong place at the wrong time.
Photo below: Two avalanche students inspect a freshly open glide crack on Tincan ~2,800′ South facing. Notice the additional cracks further along the subridge. (Photo credit: Eeva Latosuo)
Photo below is of three “brown frowns” that have opened in the pat 48-hours (Eeva Latosuo).
Yesterday was a mild day in the backcountry with partly cloudy skies, light Easterly winds and temperatures in the mid 30’s F at the mid elevations and low 30’s on the ridgetops. There has been no precipitation since Thursday’s 0.5-1″ of rain up to 3,000′.
Another mild day is in store for today. We should see partly cloudy skies with a slight bump in the Easterly ridgetop winds, into the 15mph zone. Temperatures look to remain near 30F on the ridgetops and the mid 30’s F at the mid and lower elevations.
Our next shot for precipitation is expected to arrive tomorrow afternoon in the form of rain below 2,500′ or so. This system will again usher in warm and windy conditions with moderate precipitation amounts. Stay tuned.
Looking further into the crystal ball (weather models) for later in the week and into the weekend, we will see a series of low pressure systems in the Gulf move through with showery precipitation. Slightly cooler temperatures are expected for Friday, which will help to lower the rain/snow line. However, warmer air looks to follow right behind for Saturday into Sunday, keeping the rain/snow line in the 2,000′ zone.
|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: Silvertip Creek
|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