|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.|
Light to moderate snowfall over the last three days has formed new slabs that will be easy to trigger in steep wind loaded terrain today. In areas that have not received wind and on slopes under 35 degrees the new snow has been bonding well to older snow surfaces. All reported avalanche activity in the past several days has occurred around the 2,800′ elevation. This is due in large part to snow falling on a firm surface that has encouraged propagation across slopes. While these avalanches have released snow in relatively large areas, the volume has been low enough that people have been able to avoid injury and burial. While we have limited information from the upper elevations lately, snowfall amounts and winds have been high enough above 3,000′ to create dense slabs up to 18 inches in depth. Throw into the mix new snow and winds today and slabs will increase in size and depth. Sticking to slopes under 35 degrees and avoiding wind loaded starting zones will allow for enjoyable riding and skiing conditions today.
The deep slab problem is elevation dependent. The snowpack between 1,000 and ~2,000 feet has been through four periods of warm temps, light rain and wet snow in the last month. This has helped to change the structure of the snow at the ground to the point where it is generally not a concern. However, above ~2,000 feet the snowpack is still in transition; snow pits have shown us that the weak snow at the ground is changing for the better. However, as you gain elevation the weak snow at the ground is more intact and more of a problem to pay attention to. Avoiding thin spots, steep rollovers, and terrain that doesn’t offer exit options is the best way to stay away from this problem.
It has been three weeks since a deep slab avalanche has been reported in the area. It is now very difficult to affect weak layers at the ground. The consequences still remain high, as a deep slab avalanche once triggered could entrain high volumes of snow and do a lot of damage.
Turnagain Pass has picked up 1-2″ of new snow in the past 24 hours. Winds yesterday were light but have picked up this morning and are now blowing 20mph out of the East with gusts to 36. Temps have been mild with freezing levels hovering around the 1,000′ elevation.
Snowfall should continue today, with possible accumulations in the 2-4″ range. Ridgetop winds will blow out of the S and SE between 15-20 mph with gusts up to 30mph. Temps at 1,000′ will be just below freezing.
A generally unsettled pattern will continue this week as a series of disturbances move through the area. Snowfall amounts will continue to be light and temps should remain mild and similar to what we have seen over the last several days.
Wendy will issue the next advisory tomorrow morning, February 5th.
|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|