|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
After a few very pleasant days of benign weather and easy travel, the next storm system is moving into the region. While lingering old winds slabs in steep terrain have been the primary concern, as winds increase and light snow falls, newly formed ones will become the problem today. There is settled soft snow available for wind transport as well and there is weak surface snow that the new snow will likely not bond to. Surface hoar and near surface facets have been observed from valley bottoms to ridgetops and in some locations rest on top of hard surfaces like wind crusts and melt-freeze crusts. This set-up has the potential to be very sensitive with a new wind slab on top. It will be important to pay attention to changing conditions. Watch for blowing snow, look for signs of recent wind-loading and signs of instability like cracking from your skis, board or snowmachine. The storm is forecast to ramp up this evening into tomorrow. Expect the avalanche danger to increase overnight.
Loose snow avalanches (sluffs): Observers have been reporting sluffing as they have been accessing steeper terrain during these past few days. These sluffs have been increasing in size and moving faster as the surface snow has become more faceted and less cohesive. Light snow today will add more volume. If you are in steep wind protected terrain remember these can be dangerous if they take you off your feet or push you over a cliff, into trees or other terrain trap.
Cornices: If you are traveling along ridgelines, be sure to keep plenty of distance from the edge of the large cornices that have developed throughout the area. These things have a nasty tendency to break much further back than one would expect, and could fail under the weight of a snowmachine or a skier. ***There have been reports of cornice crevasses opening up. These are another hazard to watch out for as you travel near corniced ridges.
Glide cracks are appearing throughout the forecast area and there have been glide avalanches occurring in the past few days. With these becoming a hazard in terrain where people are skiing and snowmachining, remember it is important to limit time spent underneath glide cracks. Glide avalanches are totally unpredictable, not triggered by people and are the entire snowpack sliding at the ground. This type of avalanche could be large and unsurvivable if you happened to be in wrong place when one releases. If you see recent glide activity please let us know.
Yesterday: Skies were mostly cloudy with temperatures in teens and low 20°Fs. Winds were light and easterly increasing in the late afternoon. Overnight skies were cloudy with light snow showers (to sea level) starting around midnight. Temperatures were in the teens to high 20°Fs, rising at lower elevations and falling at upper elevations. Winds were easterly 5-15 mph with gusts into the 20s.
Today: Skies will be cloudy with snow likely, 1-6″ to sea level. Temperatures will be in the 20°Fs and winds will be easterly 15-20 mph with gusts into the 30s and 40s. Overnight snow continues with an additional 5-10″ in the forecast. Temperatures remain in the 20°Fs and winds stay easterly 5-15 mph with gusts into the 30s and 40s.
Tomorrow: Snow continues but the track of the storm is still a bit uncertain making snow totals a bit of question mark. Winds will decrease and shift to the north and temperatures stay in the 20°Fs.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)
|Snow Depth (in)
|Center Ridge (1880′)
|Summit Lake (1400′)
|Alyeska Mid (1700′)
RIDGETOP 24-hour data (6am – 6am)
|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