Turnagain Pass and Girdwood

Problèmes avalancheux

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Possible

  Taille

  2–3

  Recent avalanches: January 16th and 17th marked the peak of avalanche activity across all forecast zones, with multiple natural and human-triggered avalanches recorded from Anchorage to Seward.  The last observed natural avalanche was on Monday Jan. 19th, on the south side of Tincan.  On Tuesday, Jan. 20th, a large goat-triggered avalanche was observed on Penguin Ridge, and on Wednesday, Jan. 21st, there was a (likely) remote-triggered avalanche on Sunburst that took out several sets of older ski tracks.

  Despite today being a week after the atmospheric river event, we are still tiptoeing around the mountains, hoping not to trigger a large avalanche breaking on the weak snow that lurks 2 to 4 feet under our snowmachine/board/skis. A rule of thumb we often follow, waiting a few days after a storm to let the snow settle, doesn't apply when a buried layer of weak faceted snow is involved. This kind of snowpack can be problematic for weeks after a storm. The Sunburst avalanche on Wednesday was a great example of what we are worried about: a slope releasing that already had tracks on it, large enough to bury a person. Someone who had skied that same terrain earlier in the day remarked that it was "dumb luck" that they hadn't caused an avalanche. Due to the depth of the weak layer and the hard snow above, it may feel like you can't trigger an avalanche with your skis or machine. However, snow depth is not uniform across a slope, and you may cross a thin spot and initiate a slide. Additionally, above-freezing temperatures at higher elevations can also increase the likelihood of triggering an avalanche. 

  Some points to consider for getting out in the backcountry today:

  • The snowpack is capable of producing large avalanches that could break across terrain features.
  • You may not see signs of instability before a slope releases.
  • Avalanches can be triggered after many people have been on a slope.
  • Avalanches can be triggered remotely (from the side, top, or below in the flats).
  • Thin areas in the snowpack are likely trigger spots. This includes upper elevations that were exposed to strong winds during the past storm. 
  • Watch for other groups when traveling along ridgelines. If an avalanche is triggered from a safe area along the ridge, it could threaten another group below you.

  To avoid this issue altogether, you can stick to lower-angle slopes (30 degrees or less) with nothing steeper above. If you are considering getting on steeper slopes, it is wise to choose low-consequence terrain, avoiding large slopes and terrain traps, and carefully exposing only one rider at a time.