|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.|
We received a report of a large human triggered avalanche in Ragged Bowl from a party on Goat yesterday. They thought it had occurred around 4 pm yesterday and was likely a wind slab failing on a persistent grain (weak snow). Please let us know if you have more information on this by sending in an observation or dropping a note to firstname.lastname@example.org.
|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|
The definition of MODERATE avalanche danger includes: Heightened avalanche conditions on specific terrain features. For now our snowpack sits in that box. Steep, unsupported slopes that have been recently wind-loaded warrant extra caution. The avalanche on Raggedtop, that we believe was triggered yesterday, fits into that category. In addition, observers are still reporting large whumpfs and there were human triggered avalanches on Thursday and Friday. These avalanches failed on buried facets and/or buried surface hoar in the top 1-3′ of the snowpack. On the flip side many people were out across the forecast area enjoying the sunshine with no incident yesterday. This conflicting data can be a bit confusing but is really indicative of a persistent slab issue. The bottomline is if you are heading out for some sunshine today, finding a spot where there is a slab over the buried weak snow remains a concern. The most likely place to run into trouble will be in terrain that has been recently wind-loaded, with stiff snow sitting on top of soft snow. Steep southerly aspects, where there are weak facets above and below a sun crust, may be more sensitive if there is enough of a slab over the crust facet combination.
Please watch for signs of instability, use good travel protocol, and think about terrain consequences.
Sluffs: Steep slopes that have been sheltered from the wind have around a foot or more of loose snow sitting on top of firm surfaces. It will be easy to trigger dry loose avalanches today, and they can pick up enough volume and speed to carry a person. While it is unlikely they will be big enough to bury you, they can be dangerous if they drag you into terrain traps like cliffs, trees, rocks, or gullies.
Sun effect: Be on the lookout for sun effect on steep southerly slopes, especially under rocky areas at lower elevations. Watch for the surface snow becoming moist and small roller balls.
Yesterday: Sunny skies with northwest winds 5-10 mph and temperatures with highs in the teens to high 20°Fs. Overnight skies were clear and winds remained light. Temperatures were inverted with ridgetop temperatures in the teens and valley bottoms a few degrees below zero.
Today: Mostly sunny skies becoming partly cloudy in the afternoon with easterly winds 5-10 mph, gusting into the 20s. Temperatures will be in the teens to high 20°Fs. Increasing clouds overnight with a chance of light snow showers. Temperatures will be in the teens and winds will be easterly winds 10-20 mph with gusts into the 30s.
Tomorrow: Cloudy with snow showers in the morning becoming mostly sunny by the afternoon. Temperatures in the 20°Fs and light variable winds in the morning shifting to the west, 5-10 mph in the afternoon.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||15||0||0||112|
|Summit Lake (1400′)||12||0||0||45|
|Alyeska Mid (1700′)||13||0||0||114|
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||12||N||3||19|
|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|
|11/26/23||Turnagain||Observation: Pete’s North||Ben Sullender|