Summit Lake

Avalanche problems

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Likely

  Size

  2–3

  It could be easy to trigger a large avalanche up to 3’ on several layers of buried surface hoar. While we did not hear of any avalanches in Summit Lake yesterday the same dangerous snowpack setup exists that is responsible for several avalanches in Turnagain Pass. There were several remote triggered avalanches that occurred last weekend which is enough to be concerning. The most recent layer that was buried by the Thanksgiving Day storm is likely a widespread problem that was seen from the highway up to at least 2,300’ and probably higher meaning it could exist on many slopes. 

  Unfortunately, this type of problem doesn’t always give obvious clues in the field. It is notorious for allowing several tracks on a slope and then ripping out the whole slope. It can be triggered remotely meaning that you could be traveling on a low angle slope and trigger an avalanche above you. If you want to avoid this problem the safest option is to stick to low angle slopes with no steep faces above you. If you do decide to travel into avalanche terrain, be aware that areas that seem “safer” may be more dangerous than they usually are, and that there may be no warning signs that an instability is present. Also use safe travel techniques such as using safe zones and exposing one person at a time on a slope.

  

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1–2

  There is a chance of triggering a wind slab avalanche 1’ deep or deeper from strong winds during the Thanksgiving Day storm. Today, east winds are supposed to pick up this afternoon from 10 to 30 mph with 40 to 50 mph gusts which will form a new batch of wind slabs. These could be forming earlier in the day if the winds arrive sooner than expected.

  Wind slabs can be found below ridgelines and convex rollover terrain features. The snow may feel harder and sound hollow. Keep an eye out for blowing snow and shooting cracks. Consider riding slopes sheltered from the wind that have soft snow if you want to avoid this problem. 

• 

  Glide Cracks

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  2–3

  We are becoming increasingly concerned about the large amount of glide avalanche activity this season. There seem to be more of them than in previous years. We are also noticing that instead of cracks lingering for weeks they are opening and releasing at a much faster rate. These have the potential to be destructive and travel to valley bottoms where we generally feel safe. The best option is to avoid traveling under them. If you must travel under them try to move quickly and expose one person at a time.