|Travel Advice||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.|
It has been a week since we had any report of human triggered avalanche activity and observers are not reporting signs of instability. As a mostly calm, clear and cold weather pattern dominates our area and continues into next week, we are in the “normal caution” phase of 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 specifics below in the concerns.
2- Triggering a cornice fall. The cornices maybe be small right now, but they are large enough to take you down somewhere you don’t want to go. As always, give them a wide berth.
3- Sluffs on steep slopes. These have yet to have been observed as a problem but as the surface becomes weaker under clear skies the potential will increase.
Remember LOW hazard doesn’t mean NO hazard! It is still important to look for signs of instability and use good travel techniques.
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 last Saturday and the slab character has been changing due to the cold temperatures, there are many slopes away from the ‘popular’ zones that have yet to be tested. These are the areas most suspect over the weekend. Finding the spot that harbors this weak layer, still has a slab and hasn’t been skied or slid already still could be dangerous… Triggering is unlikely but not impossible!
Buried surface hoar in a pit on Sunburst, December 6th. SW, 3200′
Several wind events over the last two weeks have formed wind slabs near and below ridgetops on a variety of aspects. Old stiff supportable wind slabs in thin rocky areas may pop once you are out onto the slab. Be wary of hard over soft snow, hollow sounds and steep slopes with obvious deposition in the start zone.
Yesterday was mostly clear above the valley fog, which crept higher as the day progressed. Temperatures were in the low 20Fs and decreased through day. Winds were light and variable. Overnight temperatures dropped into single digits in the valleys and were in the teens up high. The wind speeds bumped into the teens gusting into the high 20s from the east.
Today will be cold and clear with light easterly winds shifting to north in the afternoon. Tonight and tomorrow look very similar with temperatures getting colder through the weekend. Single digits to mid teens should be expected. This weather pattern dominates into next week. Look for a potential shift with warmer temperatures and a chance of precipitation later in the coming week.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||19||0||0||21|
|Summit Lake (1400′)||13||0||0||4|
|Alyeska Mid (1700′)||22||0||0||11|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||21||variable||6||25|
|12/03/23||Turnagain||Observation: Lipps||Paul Schauer|
|12/02/23||Turnagain||Observation: Seattle Ridge||Schauer / Keeler Forecaster|
|12/02/23||Turnagain||Observation: Tincan South Side||Anonymous|
|12/02/23||Turnagain||Observation: Eddies up track||Luc Mehl|
|12/01/23||Avalanche: Sunburst||John Sykes Forecaster|
|12/01/23||Turnagain||Observation: Eddie’s trees||Anonymous|
|12/01/23||Turnagain||Observation: Turnagain – God’s Country||Graham Predeger Forecaster|
|11/30/23||Turnagain||Avalanche: Tincan Trees||Kakiko Ramos-Leon|
|11/27/23||Turnagain||Avalanche: Tincan Ridge||Schauer/ Stiassny Forecaster|
|11/26/23||Turnagain||Observation: Road report: Slide with dirt on Repeat offender||Anonymous|