Galena Summit & Eastern Mtns

Lawinenprobleme

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Possible

  Größe

  2–3

  Triggering a large, destructive avalanche is possible. These slides would fail on persistent weak layers (crusts, crusts and facets, or facets) in the middle or bottom of the snowpack. You're most likely to trigger one of these avalanches in areas with shallower snowpacks that are commonly exposed to the wind.

  Several natural and human-triggered avalanches have been observed in this zone over the past week (Observations and Avalanches). Avalanches have occurred on many aspects, frequently in wind-loaded, alpine terrain.

  Persistent Slab avalanches can release in surprising ways. You can trigger them from flat or low-angle terrain long distances away from steep slopes, and they can break far above you. They can break hundreds or thousands of feet wide and after several riders or skiers have safely crossed the slope. Before triggering an avalanche, you may not experience snowpack collapsing or other obvious signs of instability.

  Avoid obviously wind-loaded slopes to reduce the chance of triggering these avalanches. 

  

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Possible

  Größe

  1–2

  You could trigger recently formed wind slabs in exposed terrain near ridgelines. Natural avalanches are possible in alpine terrain. The slabs will be larger, more widespread, and probably easier to trigger both as you climb in elevation and as this afternoon's wind builds new and existing slabs.  

  Some of the wind slabs overlie crusts and crust + facet combinations; in these areas, avalanches could be easier to trigger, could release naturally, and could break wider than expected. Small chunks of cornice that you break off or that fall naturally could trigger wind slabs on the slopes beneath them. 

  Fortunately, managing this problem is straightforward; avoiding wind-loaded slopes will significantly reduce the chances you find trouble. Watch for fresh cornices, dunes, rippled snow surfaces, and areas with stiffer snow surfaces. These are clues that the wind has been at work. Cracks shooting out in front of your skis or boards mean you've probably found a wind slab.

  Additional Discussion: Relatively small, wet loose avalanches are possible on wind-sheltered slopes facing the southern half of the compass below about 7500' in elevation. These slides could release naturally and will be most likely this afternoon as surface crusts melt and turn to mush.