|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.|
|Signal Word||Size (D scale)||Simple Descriptor|
|Small||1||Unlikely to bury a person|
|Large||2||Can bury a person|
|Very Large||3||Can destroy a house|
|Historic||4 & 5||Can destroy part or all of a village|
Today we should see the third pulse in a series of warm storms impact the region. Temperatures climbed to 32F at 2,500′ yesterday, bringing rain as high as 2,200′. Today those numbers are expected to increase. Another 0.5″ of rain up to 2,500′ is forecast with 0.7″ tonight. In the alpine (above 2,500′) an additional 6-8″ of snow should fall today and 8-10″ tonight. Snow will be accompanied with winds in the 30’s and 40’s along the ridgetops from the east.
It is unknown the extent of the avalanche activity yesterday at the upper elevations due to limited visibility, but we did get a photo sent in to us of wet loose avalanches on the west face of Magnum at Turnagain Pass (thank you!). These avalanches were due to rain on snow, which will be expected again today. Obscured in the clouds at the high elevations we are expecting storm snow avalanche activity to continue. The new snow is piling up on a slick hard surface left from last week – which was a hard crust likely topped with surface hoar. This set up should be producing slab avalanches and as soon as the clouds part we’ll be doing our best to take stock.
Storm totals at the mid-elevation snow stations for this soggy storm cycle:
State of the snowpack? Although the snowpack is thickening in the high mountain terrain we are loosing the little snow that was there at the mid-elevations. Before this storm there was roughly 2-3′ of snow depth at 3,300′, that should be close to doubling after today’s snowfall. At 2,200′ and getting higher … bare ground is taking over as rain is washing away the few inches of snow remaining.
Hard to see, but there are wet loose point release avalanches on the west face of Magnum, seen from the Center Ridge trail (Photo: Jacob Swartz).
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||35||3″ wet snow (with some rain)||1.2||15|
|Summit Lake (1400′)||35||1||0.3||0|
|Alyeska Mid (1700′)||35||Rain||1.9||0|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||32||SE||20||57|
|12/04/23||Turnagain||Observation: Lynx Creek||Schauer / Keeler/ Predeger Forecaster|
|12/04/23||Turnagain||Observation: Sunburst, 2400′ – 3100′ NW ridge common uptrack.||Arnav Verma|
|12/03/23||Turnagain||Observation: Center Ridge||Amy Holman|
|12/03/23||Turnagain||Observation: Magnum||Tony Naciuk|
|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|