Summit Lake

Problemi valanghivi

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alta quota
  • Limite del bosco
  • Sotto il limite del bosco

  Probabilità

  Very Likely

  Dimensione

  1.5–2.5

  New wind slabs 1 to 3’ deep will be easy to trigger on slopes exposed to the wind. The storm is forecast to deliver strong ridge top winds out of the east averaging 20 to 40 mph with 70+ mph gusts and a few inches of snow before the sun begins to set. As the wind ramps up in the afternoon the avalanche danger will increase. This will make it easier for a human to trigger fresh wind slabs and increase the likelihood of natural avalanches. There is also a chance that triggering a wind slab avalanche may trigger a larger avalanche failing on a weak layer deeper in the snowpack. If you do get out today, avoid slopes that are being loaded with wind blown snow. As the avalanche danger increases weather conditions may warrant avoiding avalanche terrain altogether. 

  If the winds verify slopes sheltered from the wind below 2,500’ will be the safest option. Keep in mind that at mid elevations wind slabs may also be forming in areas exposed to the wind. You can probe for wind slabs by feeling firm snow over soft snow. Shooting cracks underneath you is also a clue you are traveling on a wind slab. Approach slopes cautiously looking for these clues. Be prepared to change your travel plan choosing lower angle slopes as conditions become more dangerous. 

  Cornice: Large cornices that formed from the storm last weekend will continue to grow today. This storm may be the tipping point for these to fall and trigger a natural avalanche above you that could be larger than expected and run to valley bottoms. Limit exposure under slopes where this overhead hazard exists.

  Dry Loose Avalanches: There is a chance for a human to trigger a dry loose avalanche on steep slopes. Natural dry loose avalanches were observed in Turnagain Pass and Summit Lake yesterday. Watch out for these as they can carry you off cliffs and into terrain traps. 

  

• 

  Deep Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alta quota
  • Limite del bosco
  • Sotto il limite del bosco

  Probabilità

  Possible

  Dimensione

  2.5–3.5

  There are several weak layers in the snowpack that could create a large avalanche 2 to 4’ deep. Yesterday on Tenderfoot we heard whumpfing at 3200’ where the snow was thin near some exposed rocks. These are areas where it will be easy to trigger a deep slab avalanche. 

  This type of problem can be very hard to assess and has the potential to produce large avalanches. We do know that tests in our pits are still producing concerning results and there was a widespread avalanche cycle last week that failed on weak layers deep in the snowpack. Blowing snow today will also add weight on top of these weak layers. This added stress will increase the chance of triggering a large avalanche today so we recommend avoiding steep slopes. The safest option is to ride on lower angle slopes sheltered from the wind.