|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.
Over the weekend many people were out in the mountains slope testing and there were no human triggered avalanches reported. With a stable weather pattern dominating our region and very little changes affecting the snowpack we are in a Normal Caution phase for avalanche issues. These include:
1- Triggering an outlier avalanche. This would most likely be an ‘unsupported slab’ that sits above a cliff or steep rocky terrain. More on this below in ‘Additional Concerns.’
2- Triggering an old wind slab – Avoid hard stiff snow sitting in steep rocky terrain where a small isolated wind slab could have high consequences.
3- Triggering a cornice fall. Cornices are small right now, but similar to wind slabs they could take you down somewhere you don’t want to go. Give cornices a wide berth.
4- Sluffs on steep slopes. Small sluffs were observed yesterday, and as the surface snow becomes weaker under clear skies the potential for bigger stuff will increase.
Remember LOW hazard doesn’t mean NO hazard! Look for signs of instability and use good travel techniques.
Final ridge up Pastoral, near 4400′ Photo: Andy Moderow
Even with LOW avalanche danger it is still important to remember the weak layer 1-2′ below the surface i.e. the notorious Nov 16th buried surface hoar. Although we have not seen an avalanche release in this layer since December 3rd and the slab character has been changing due to the cold temperatures, there are still slopes away from the ‘popular’ zones that have yet to be tested. These are the areas most suspect. Triggering is unlikely but not impossible!
Yesterday was cold, clear and calm. An inversion kept ridge top temps in the teens to low 20Fs and lower elevations in the single digits or below zero. This was true overnight as well.
Today and tomorrow will be similar with clear skies, light N-NW winds and temperatures ranging from single digits in the valleys to teens and low 20Fs at higher elevations.
According to the NWS “the rather stagnant weather pattern will be changing dramatically” later in the week. Precipitation and warmer temperatures are forecasted. Stay tuned!
|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: 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
|Avalanche: Base of Seattle Ridge
|Troy Tempel, Thomas Lees, .Josh Bollaert, Damian Naquin