|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.
|Size (D scale)
|Unlikely to bury a person
|Can bury a person
|Can destroy a house
|4 & 5
|Can destroy part or all of a village
Observers continue to find the buried persistent weak layers in the snowpack to be reactive and the possibility of triggering a large avalanche remains. One observer yesterday found the January 21st buried surface hoar, described the snowpack they found in Lynx Creek as “spooky” and changed their plan due to concerning snowpit test results. This buried surface hoar layer was also observed to be reactive on Magnum yesterday as well. As snow starts today and hopefully falls throughout the week it will be important to remember the current state of the snowpack. Buried 1-2′ deep are facets sitting on a crust at the mid-elevations and 1-3′ deep is a buried surface hoar/facet combo at the higher elevations. The slab over the weak layers could be very hard if it is in terrain that was affected by the strong winds last week. This was the case in the skier triggered avalanche in Summit Lake a week ago, the mid-elevation faceted layer was under very hard wind-affected snow. Although the heart of Turnagain Pass has the buried weak layers, they are more pronounced and developed on the Southern end of Turnagain Pass and in Summit Lake where the snowpack is shallower. Areas to the North, such as Crow Pass, are also suspect along with those that have not seen much traffic this season. Using safe travel protocols and assessing the consequences if a slab does release is key in choosing terrain. Weak layers like these can become more reactive after even a small additional load. As the snow falls this week keep that in mind and as always be alert for signs of instability.
Wind slabs: Hard wind-affected snow on steep, unsupported slopes may still triggered if you find the wrong spot. Be suspect of very stiff snow over soft snow or hollow sounding snow near upper elevation ridgelines and cross-loaded gullies. If winds really pick up this afternoon pay attention to changing conditions.
Snowpit on Magnum yesterday at 3100′. The January 21st buried surface hoar is easy to spot and still reactive in stability tests.
Cross-loaded gullies on Seattle Ridge
Yesterday was mostly to partly cloudy with some afternoon sunshine peeking through. Temperatures were in the teens to mid 20Fs. Winds were light and variable. Overnight temperatures were in the teens to low 20Fs and winds remained light.
Today will be mostly cloudy with afternoon snow showers. Temperatures will be in the teens to high 20Fs and winds will start off light and increase from the Southeast 10-20 mph gusting into the 30s. Tonight there is snow in the forecast with 2-6″ possible. Temperatures will be a bit cooler in the low 20Fs to mid teens. Winds will continue from the Southeast.
Tomorrow’s forecast has continued snow showers in the morning, clearing in the afternoon and then more snow in the forecast overnight. The next low pressure is lining up for more snow on Thursday but details are uncertain. However, the week ahead looks to be snowy. From the NWS discussion this morning: Despite March and April being the driest months of the year (climatologically), Mother Nature is giving that statistic a run for its money. Fingers crossed!
|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: 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
|Observation: Lynx creek