|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.
Warm temperatures and heavy rain is weaken the snowpack in the mid elevation band. In the last 24 hours 1.8” of water (rain) fell below 1600’ and today another 1” of water is expected to fall by mid-day. This amount of water in the snowpack is increasing the likelihood for large natural wet slabs and wet loose avalanches. This is the type of snow that if a human triggers a wet avalanche it can be impossible to escape from. Our observations yesterday (video below) shows how unsupportable the mid-elevation snowpack was before the additional rain overnight and today. The only way to manage this avalanche problem is by avoiding avalanche terrain all together. Stay off of slopes steeper than 30 degrees, and maintain a safe distance from all run-out zones.
Yesterday several new piles of wet debris were seen from the road along the East face of Seattle Ridge including this wet slab seen near Ingram Creek from the Seward Hwy.
Today expect strong Easterly winds and an additional 12-15″ of new snow above 1900’. This is on top of a 7-day stretch of very precipitous stormy weather that has produced and estimated 12’ of snow in the alpine and several days of above freezing temperature along Turnagain Pass road (1000′). In the upper elevations natural cornice fall and wind slab activity are likely. These dry avalanches from above could easily run into the mid elevations and entrain wet snow to the valley floor. Again this is another reason not to go into avalanche terrain today.
Rain will continue to weaken the snowpack where existing glide cracks litter the mid elevation zones. Over the last two days a handful of glide avalanches have occurred in steep terrain and it is likely more will release today. Glides threaten a lot of well-travelled terrain on both the motorized and non-motorized side of the highway. This concern is listed in the ‘Additional’, but is side by side with all of the above avalanche problems for today. Today is not a good day to play in the mountains.
Recent glide release on the N side of Eddies, seen from the Seward Hwy yesterday. Click HERE to see more glide observations from the last three days.
Overnight 1.8 € of water fell at Center Ridge weather station (1800′) where temperatures remained just cool enough for snow (~18 €.) Easterly winds averaged in the 30’s mph with a gust to 73 mph on Sunburst. Overnight temperatures cooled briefly along Turnagain Pass (1000′) for a short period of wet snow, but temps have already increased to 34F this morning.
Today 1 € of water is expected to fall in the form of rain below 1600′ and 12 € of new snow in the alpine. Warm temperatures could push rain/snow line as high as 1900′. Strong NE winds 30-40mph hour are anticipated along ridgetops. Intensity is expected to lessen by late afternoon, early evening.
Tomorrow showery conditions will persist in the form of rain and snow with the first hope of a break in precipitation Monday evening.
|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