Avalanche Advisory

Turnagain Area Avalanche Advisory Friday, December 27th 2013 6:20 am by Kevin Wright ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.

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Continued red flags, including whoomphing (collapsing) in the snowpack are keeping the danger rating at MODERATE above treeline. Steeper slopes should be approached with caution, as the slab/weak layer problem is well understood.  Despite the duration we've had without new snow, lingering instability is keeping us wary of steeper terrain.

Snow is forecasted for this evening, meaning a small increase in the avalanche danger is expected tomorrow.  

Show the Complete North American Avalanche Danger Scale

North American Public Avalanche Danger Scale Avalanche danger is determined by the likelihood, size and distribution of avalanches. Danger Level Travel Advice Likelihood of Avalanches Avalanche Size and Distribution 5 Extreme Avoid all avalanche terrain. Natural and human- triggered avalanches certain. Large to very large avalanches in many areas. 4 High Very dangerous avalanche conditions. Travel in avalanche terrain not recommended. Natural avalanches likely; human- triggered avalanches very likely. Large avalanches in many areas; or very large avalanches in specific areas. 3 Considerable Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential. Natural avalanches possible; human- triggered avalanches likely. Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas. 2 Moderate Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern. Natural avalanches unlikely; human- triggered avalanches possible. Small avalanches in specific areas; or large avalanches in isolated areas. 1 Low Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features. Natural and human- triggered avalanches unlikely. Small avalanches in isolated areas or extreme terrain. Safe backcountry travel requires training and experience. You control your own risk by choosing where, when and how you travel.

2 Moderate Alpine / Above 2,500'

Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

1 Low Treeline / 1,000'-2,500'

Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1 Low Below Treeline / Below 1,000'

Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Check out this Kickstarter project for an all female ski movie.  The project will include filming within our own Chugach National Forest, and will have local talent in the cast.  It will be used as an educational tool for avalanche awareness trainings with SheJumps.  The project is soliciting support and has 20 days to the deadline.

Avalanche Problem 1

The poor structure of the snowpack is the culprit behind the collapsing that's keeping us worried.  The most reactive layers we've been seeing are the facets above the early December "drizzle" crust (see pit profile here).  This layer is showing a tendency to propagate in some pit tests, and we believe it is the big player in most of the recent natural and skier triggered avalanches. 

Check out Fitz's video for a discussion of managing the Moderate problem on Thursday.

Avalanche Problem 2

There remains some evidence of wind slab avalanche activity from the wind storm on Monday.  On Thursday we found numerous mid slope crown lines near Crow Pass from avalanches that presumably happened during that wind event.  We can expect some areas to be holding stiff wind slab that didn't slide spontaneously, but may be triggered by a person hitting a trigger point.  

Weather has been consistently benign since Monday with cold, clear, and calm conditions.  Temperatures are a little warmer at the ridgetops today, so don't let cold Anchorage temperatures keep you at home today.  

Look for increasing clouds today, and snowfall is expected to commence tonight in Eastern Turnagain Arm.  Up to 4-8 inches of snow is in the forecast for tonight!  

The storm will be short lived as the front sweeps across southcentral Alaska, with snow tapering Saturday morning and ending.

This is a general backcountry avalanche advisory issued for Turnagain Arm with Turnagain Pass as the core advisory area (this advisory does not apply to highways, railroads, or operating ski areas).

Riding status is not associated with avalanche danger. An area will be open to motorized use in accordance to the Forest Management Plan when snow coverage is adequate to protect underlying vegetation. Backcountry hazards including avalanche hazard are always present regardless of the open status of motorized use areas.

(Updated: Dec 01, 2018 )

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