Thursday, January 9th 2014 6:43 am by Kevin Wright
ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.
Persistent slab concerns keep us at CONSIDERABLE above treeline. The overall stability trend is very slowly improving, but large human triggered avalanches are still likely in specific areas. Another avalanche near Summit Lake yesterday emphasizes that point.
Slopes above treeline, greater than 35 degrees, and in shallower areas or complex terrain should be avoided. If an avalanche is triggered today, it is likely to be large, 2-3 feet deep, may be triggered remotely, and cause connected slopes to avalanche sympathetically.
|Show the Complete North American Avalanche Danger Scale|
|Travel Advice: Dangerous avalanche conditions. Careful snowpack evaluation, cautious routefinding and conservative decision-making essential.|
|Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.|
The persistent slab problem continues to trend toward less likely, but large high consequence avalanches will result if triggered. Snow pits are showing mixed results now... Sometimes the layers are not reacting. It's worth keeping in mind that all pit information is overruled by other signs and symptoms. Collapsing, or recent avalanche activity means that the snowpack is inherently unstable, and steeper slopes can slide.
The photo below is from yesterday on Tenderfoot at Summit lake. Click here for a writeup and another photo. The Summit region is often a poor comparison to Turnagain Pass or Girdwood, but right now it represents what any shallower snowpack areas can do. This is another remotely triggered avalanche, one of many in the past week.
Recent snowfall (over 2 feet of wet snow in the last 10 days) has now consolidated into a fairly strong and connected slab. This is good because it is now more difficult for a person's weight to penetrate that dense layer and collapse the weaker snow at or below the drizzle crust. However, it's bad because the resulting avalanche when a trigger point is found is now larger and more dangerous. The likelihood of triggering has decreased, but the avalanche size and destructive force has increased.
Trigger points are likely to be shallower wind stripped pockets, possibly close to exposed rocks or trees.
A few inches of snow have accumulated since Tuesday. In general, the weather has not contributed a lot to the avalanche danger since the larger storm on Saturday/Sunday.
Today, mostly cloudy skies are expected. Isolated snow showers are in the forecast today and tomorrow, with little accumulation. Wind should be light. Temperatures continue in the 20s, with a slight decreasing trend on Friday.
Watch for aurora displays tonight if the skies are clear enough. A large solar storm may bring active displays to lower latitudes.
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: May 06, 2018 )
|AREA||STATUS||WEATHER AND RIDING CONDITIONS|
|Johnson Pass:||Closed||Closed as of April 20th|
|Placer River:||Closed||Closed as of April 17th|
|Skookum Drainage:||Closed||Closed as of April 1st.|
|Turnagain Pass:||Closed||Closed as of May 7th. Happy summer, see ya when the snow flies!|
|Twentymile:||Closed||Closed as of April 13th|
|Carter Lake:||Closed||Closed as of 4/27|
|Lost Lake Trail:||Closed||Closed as of April 13th|
|Primrose Trail:||Closed||Closed as of April 13th|
|Resurrection Pass Trail:||Closed||Closed as of April 20th|
|Snug Harbor:||Closed||Closed as of 4/27|
|South Fork Snow River Corridor:||Closed||Closed as of April 13th|
|Summit Lake:||Closed||Closed as of April 20th|
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