|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.|
With the exception of a few inches of snow that fell in the Placer/Skookum zone on Thursday morning, it has been 24 days without precipitation in our region. Surface conditions are made up primarily of thin crusts, hard wind board on ridges and near surface facets (recycled powder) in areas sheltered from the recent winds. Although the avalanche danger has been at LOW for almost two weeks, there are a handful of avalanche problems that could catch you off guard in dangerous terrain. Be aware of the following:
Wind Slabs: Old stiff wind slabs, such as the one triggered on Seattle ridge last weekend, will be stubborn to trigger. Smooth pillowed snow on steep unsupported features or in rocky areas will be the most suspect places to initiate an old wind slab. Small fresh wind slabs are also possible near ridgetops surrounding the Skookum/Placer Valley due to recent snow (2-3″) and moderate winds that kicked up yesterday afternoon.
Loose Snow Avalanches (Sluffs): Loose unconsolidated snow can still be found, and could be fast moving in steep terrain. In Skookum/Placer new snow may be easy to initiate and wet-loose point releases are possible on Southerly aspects due to solar heating. These will likely be small, but keep terrain choices and potential consequences in mind when managing sluff.
Glide Avalanches: Glide cracks continue to slowly open above popular terrain on Seattle Ridge and in other zones across the advisory area. These may release at any time. Minimize exposure time spent under visible cracks.
Cornices: Cornices should always be given an extra wide berth if traveling along a corniced ridge. Like glide cracks, minimize your exposure time spent under these backcountry bombs.
Persistent Slabs and Deep Slabs: There are various weak layers in our thin snowpack. Buried surface hoar sits 1-3+’ below the surface and faceted snow sits in the mid and base of the pack. Given plenty of time and a lack of changing weather, these weak layers (with varying degrees of strength) are in a ‘dormant stage’. Although unlikely, an avalanche breaking deeper in the pack isn’t completely out of the question in areas such as Johnson Pass, Lynx Creek and on the Northern side of Girdwood Valley (near Crow Pass).
Surface conditions around our region are highly variable
Yesterday was another clear and sunny day. Daily warming caused temperatures in the single digits F to increase into the low 20F’s by mid day. Ridge top winds, 5-15mph, varied in direction from Southwest to Northeast. Overnight temperatures dropped back into the single digits F.
Another clear and sunny day is in our future. Temperatures are expected to rise from the single digits into the low 20’s – a similar pattern as yesterday. Ridgetop winds are expected to be light and variable. No precipitation is expected. By evening light cloud cover is anticipated and temperatures should remain in the teens F overnight.
Tomorrow scattered snow showers are possible, but not much accumulation is expected. High pressure over mainland, Alaska continues block a series of fronts in Gulf of Alaska, just South of us. Luckily there is a pattern shift is in the forecast late this week as the €œpolar jet weakens over the northwest mainland. € At this point there is not a lot on the horizon for snow, but this is a good first sign.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||6||0||0||59|
|Summit Lake (1400′)||4||0||0||28|
|Alyeska Mid (1700′)||10||0||0||56|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||6||NE||5||19|
|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|