|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.
Yesterday Moderate Northwest ridgetop winds were seen blowing snow throughout our region loading many South and East aspects. Plenty of snow was available for transport and fresh wind slabs 1-2’ deep could be tender today. Steep, unsupported, leeward slopes in the alpine are the most suspect and a slab could break above you. Be on the lookout for drifted snow that has a pillow shaped appearance and don’t be surprised if slopes are loaded further down hill than expected. Evaluate the snow as you travel by testing small slopes and avoid high consequence terrain where the snow feels stiff, supportable or hollow sounding. Shooting cracks will be obvious clue that the snow is unstable.
In Girdwood wind slabs may be thicker and could step down to an older weaker layer below. More caution is advised in this area.
Blowing snow along ridgetops was observed throughout the region yesterday, including the Placer Valley as seen below. Photo by Conrad Chapman.
Today in areas protected from the wind triggering a loose snow avalanche will be possible on steeper slopes. Fast moving “sluff” could entrain snow, run further than expected and easily knock you off your feet. Manage this problem by letting the snow move past you and choose terrain that doesn’t have high consequences if you fall. Although it is unlikely to bury a person, keep in mind that larger terrain will have more volume. Cold temperatures could increase this problem throughout the week as the surface snow becomes even less cohesive.
A variety of weak layers exist within the snowpack and vary across our region. Following the most recent snowstorm (1/13-1/16) most of the avalanche activity has been observed in the Girdwood Valley. This makes sense since this storm favored this area and left 2-3’ of snow. A handful of small, but deep (to the ground) avalanches were spotted in the alpine yesterday on Southern aspects of Penguin Ridge, Raggedtop, and Magpie. It is unconfirmed if these all happened as a result of moderate NW ridgetop winds that started yesterday morning or if these happened near the end of the storm on Monday (1/16.) Either way triggering even a smaller persistent slab could bury a person or take you for a very unfavorable ride over rocks. If you see recent avalanche activity, experience shooting cracks, or “whumpfing” these are obvious clues that you should avoid steep slopes.
If traveling in the Placer and 20 mile zone, where we have little information about the snowpack, use caution if venturing into steep untested slopes. An observation yesterday confirmed significant wind transport along ridges in this area and there is also a possiblity of triggering a slab on an older deeper layer of the snowpack. It always advised to ride slopes one at a time, have a escape route planned, watch your riding partners and avoid terrain traps like steep gullies. Ease into terrain and let us know if you see an signs of instability today.
Recent avalanche activity in the Crow Pass area on South aspects of Magpie. More photos of recent avalanche activity in Girdwood Valley can be found HERE.
Yesterday skies were clear and temperatures hovered between 0F to -5F. Northwest winds bumped into the 20-35mph range along ridge tops and remained moderate overnight. No new precipitation was recorded.
Today looks similar with temps around 0F and another day of clear skies. NW winds will continue to blow 10-20mph, but should decrease by late afternoon to 5-15mph range.
Tomorrow expect a slight increase in temperatures (15F) and a possibility of scattered snow showers. There is talk of the cold arctic over Southcentral, AK breaking up as low pressure tracks into the Gulf late this 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: Bertha Creek
|Schauer/ Cullen Forecaster
|Observation: Magnum & Cornbiscuit
|Moderow / St. Clair
|Observation: Tincan Backdoor
|APU Snow Science I
|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