Summit Lake

Lawinenprobleme

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  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Likely

  Größe

  2–3

  Recent avalanches:  An observer noticed just one small new avalanche in the Summit area yesterday on Summit Peak, but several large avalanches occurred yesterday afternoon near the Hope junction and just north of there on the border of the Summit and Turnagain Zones. A widespread natural avalanche cycle occurred in Summit Lake last week. Large avalanches were observed on Moose Mtn, Roaring Ridge, Manitoba, Butch, and Raven's Ridge.

  The snowpack in Summit Lake is thinner than its neighboring zones and the weak layer of facets buried up to 3' deep is more sensitive to the weight of a person. The weight of the water (0.3") and wind (20 to 30 gusting to 60 mph) that came yesterday added stress to this weak layer. It could be easy for a person to trigger a large avalanche on this layer today. There may or may not be any red flags like whumpfing or shooting cracks prior to one of these avalanches releasing. An avalanche could be triggered even if there are many tracks already on the slope. The safest plan today involves terrain that is less than 30 degrees and does not cross under steep slopes above. Even small features could be a problem if they end in a gully where snow could pile up. If you find yourself traveling in steep terrain ensure only one person at a time is exposed and others are staged in spots that are safe from runout.

  

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  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Very Likely

  Größe

  1–2

  There is a break between storms today, but there are a variety of wind slabs that could be easy for a person to trigger today in the alpine. Easterly winds were blowing in the 20s and 30s mph on Summit Peak yesterday. Above 2,500' where precipitation was falling as snow, fresh wind slabs were forming up to 1.5' deep. Easterly winds up to 30 mph are forecast again today. With winds this strong, wind slabs could be anywhere in exposed areas, but especially under ridgelines and on steep rollovers. Keep in mind that triggering a new wind slab could be enough weight to trigger a much larger and more dangerous avalanche described above.

  Wet loose: Temperatures are still warm this morning so surfaces may still be wet and wet loose avalanches may still occur. Watch for rollerballs to know a person could trigger one of these avalanches.