|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.|
Observations from the field yesterday found a moist surface up to at least 3200’ in the wake of the Sunday/ Monday warm up. Unfortunately this wasn’t only relegated to solar aspects but shadier north aspects were harboring a moist surface as well. The weekend storm snow is settling out rather rapidly, compressing the several inches of cooler, low-density snow (from Saturday morning) into a thin weak layer 6-16” below the surface. In steep terrain, wet-loose snow yesterday was easy to initiate, building enough mass and momentum that it could pose a problem for a skier in consequential terrain. These are relatively small but heavy and powerful avalanches that are difficult to escape from. Keep this in mind as you are travelling above any terrain traps such as gullies, trees, cliffs or glide cracks. Snowmachiners: The surface is such right now that you can entrain a significant amount of heavy wet snow as you descend. It’ll be prudent to ‘manage’ this heavy sluff and avoid terrain traps.
Last night was the second night in a row where temperatures did not freeze overnight below about 2,000’ making for a punchy, rotten snowpack. If temperatures do spike again today in the afternoon or we receive significant rain on snow, it’s entirely possible that wet loose avalanches could pull out dangerous wet slabs in this mid-elevation band.
Wet loose avalanches skiers-right of Todd’s run. Eddies glide crack-complex in the background.
Roller balls are another good clue to a warming surface, primed for wet-loose avalanches.
Good visibility allowed us a look around yesterday to add to a growing list of glide avalanches across the region. The post-storm tally was 3 new glides: Penguin ridge, Skookum Valley and Seattle ridge (N. of uptrack). As long as glide cracks continue to open up, move and release, we will stress the importance of avoiding them, which is THE ONLY WAY TO MANAGE THIS AVALANCHE PROBLEM. Remember, this is the entire winters snowpack releasing to the ground suddenly and without warning. Simple avoidance of glide cracks continues to be the key.
CORNICES: We did see some active cornice shedding during the heat of the day yesterday. Take extra precautions when travelling around cornices as they tend to break much further back on ridges than often times expected.
Winds have been cranking enough in the alpine to transport any available snow into shallow wind slabs. Likely these will be found somewhere above 3500’ today where the snow surface dries out. 2-4” of new snow forecasted and moderate easterly winds in the upper elevations today will add to existing wind slabs in the 1-2’ range.
The most notable aspect to yesterday’s weather was the warmth in the air. 40-degree temps are finally acting to melt out some of the SUV-swallowing potholes in the motorized lot at 1,000′. Pavement is again visible! Ridgetop temperatures spiked at 34 degrees in the afternoon on the top of Sunburst (3800′). Just a trace of precip was measured yesterday morning before skies broke mostly sunny. Winds were light (gusting into the 20’s) from the East before picking up overnight.
Today we can expect up to another half inch of water throughout the day with a rain/ snow line around 2,000′. Winds will be from the east in the 20-30 mph range. Temperatures will again be unseasonably warm in the high 30’s to low 40’s at 1,000′.
The well-developed low tracking North into the Gulf today may not influence us much tomorrow as a persistent upper level ridge looks to limit its advance onto the mainland.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||39||0||.2||131|
|Summit Lake (1400′)||39||0||.3||45|
|Alyeska Mid (1700′)||37||0||n/a||109|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||33||SE||18||39|
|11/27/23||Turnagain||Avalanche: Tincan Ridge||Schauer/ Stiassny Forecaster|
|11/26/23||Turnagain||Observation: Road report: Slide with dirt on Repeat offender||Anonymous|
|11/26/23||Turnagain||Observation: Pete’s North||Ben Sullender|
|11/25/23||Turnagain||Observation: Tincan trees||John Sykes Forecaster|
|11/21/23||Observation: Spokane Creek||John Sykes Forecaster|
|11/19/23||Turnagain||Observation: Magnum – PMS Bowl||Schauer/ Cullen/ Jonas Forecaster|
|11/19/23||Other Regions||Observation: Sunnyside/Penguin||Jose Ramos-Leon|
|11/19/23||Turnagain||Observation: Eddies||Andy Moderow|