|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.|
The storm that ended Wednesday left 6-8 inches of light density snow sitting on the surface. This snow will sluff easily today, primarily on North and West aspects and especially in steeper terrain. South and some East facing terrain received enough sun yesterday to melt the surface snow which has re frozen overnight where loose snow avalanches are less of a problem. Natural point releases were observed on multiple aspects above treeline yesterday. Expect more of the same today with sluffs being small to medium in volume. Pay particular attention to these above terrain traps such as cliffs, gullies and trees.
There is the possibility of finding isolated older pockets of shallow wind slab in the higher elevation starting zones. Triggering one of these smaller slabs combined with sluffing will increase the volume of snow moving dowhill, making it harder to manage terrain appropriately.
A distinct buried crust resides in many locations between ~1,500-3,000′ in elevation. On top of this crust is weak snow in some areas. On top of that weak snow is a slab up to 3 feet thick. Yesterday my partners and I tested the snow at this interface and found it to be non reactive. Other areas in the last week have shown this layer to be reactive and because of this it is still worth paying attention to. Staying off of steep rollovers and thin spots, especially slopes getting direct sun will help in avoiding this problem today.
We also looked at some thin spots in the snowpack to assess the deep slab problem. Weak snow still exists at the ground above 2,000′. Our tests yesterday showed this weak snow to be non reactive, for now.
In the past 24 hours the mountains around Eastern Turnagain Arm have picked up a trace of new snow. Winds have been very light out of the North and Northwest and temperatures have been in the teens at ridgetops. The sun made an appearance for several hours during the day yesterday and has created crusts on South aspects.
Today expect to see lingering snow showers giving way to clearing skies in the afternoon ahead of the next approaching disturbance. Winds will blow 10-20 mph out of the Northwest and temperatures at 1,000′ will be in the mid twenties.
Light snowfall should resume late tonight as a series of weak disturbances continue to move through the area over the next several days.
Kevin will issue the next advisory tomorrow morning, February 23rd.
|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|