|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.|
Storm Slabs: Today is day 3 of a warm and wet storm that has dumped 3″ of water (2-4′ of new snow in the upper elevations) in the advisory area. This has fallen on old weak (faceted) snow resting on a rain crust. The storm snow was not bonding well to this yesterday and was reactive in tests, whumpfing, cracking and became increasingly ‘slabby’ throughout the day. Because the crust/facet combo extends from 1000′ to approximately 3000′ avalanches could be very large and connected. The storm last week stabilized quickly. It is important to recognize the character of this set-up is very different and could elevate the hazard through the weekend. Travel in avalanche terrain is not recommended today.
Wind Slabs: Stormy conditions continue to make wind slabs a concern for the upper elevations. Sustained 30-40 mph ENE winds, gusting in the 70s yesterday, have made triggering a wind slab +3’ thick likely on wind loaded and cross-loaded features. Below 3000’ these wind slabs are sitting on the old snow/crust combo and may propagate further than expected.
Cornices: Cornices will be unstable today and may release naturally. These features have been tender over the last week and now have the added stress of high winds and new snow. These backcountry bombs can easily trigger a slab below and are another reason to avoid travel in avalanche terrain today.
Wet Snow: Wet snow is sitting on a slick crust in the mid elevation band. Rain to 1600’ will be lubricating this poor interface making wet avalanches possible in the mid elevation band. This hazard will be especially dangerous under big open slopes and in terrain traps like gullies or abrupt transitions where an avalanche from above could have high consequences. Natural activity is possible in steep channeled terrain and will likely entrain wet snow. Areas like lower Seattle Ridge should be avoided.
Warm temperatures, rain and wet snow continue to add weight and stress to glide cracks throughout Turnagain Pass. These unpredictable hazards are widespread in steep terrain between 1000’ to 2500’ and can release without warning. Today’s limited visibility will make it challenging to identify existing glides, and is an added reason to avoid being in the mountains today.
Yesterday was a storm day. Rain fell up to 1500′ and the advisory area recieved another 1.5″ of moisture. Snowfall was up to an 1″/hr for much of the day with over 1′ of new snow falling in the last 24 hrs. Since Tuesday evening 3″ of water and +3′ of snow have fallen. Winds were from the ENE blowing 30-40 mph gusting into the 70s. Temperatures were in the 30Fs at 1000′ and the mid-20Fs at 3000′.
Rain and snow showers are forecasted to continue today with an addtional 0-4” of snow and rain up to 1600′. Winds will be Easterly 15-25 mph and temperatures will be in the 30s.
Showers continue this evening tappering off overnight with a short break before the next Low impacts the area Sunday.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||31||10||1.7||114|
|Summit Lake (1400′)||32||3||.3||31|
|Alyeska Mid (1700′)||32||9.5||1.3||84|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||26||n/a||n/a||n/a|
|12/06/23||Turnagain||Observation: Eddies||N Dumont|
|12/05/23||Turnagain||Observation: Sunburst||Kakiko Ramos-Leon|
|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: West ridge of Tincan Peak and Peak 4400||Kelli Spencer|
|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|