Galena Summit & Eastern Mtns

Lawinenprobleme

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Possible

  Größe

  1–2

  Skiers and riders triggered several slab avalanches in the past week. All involved persistent weak layers (crusts and facets, facets) in the upper 1-2 feet of the snowpack. Some were triggered remotely—from gentler terrain above, below, or to the side of the slab (photo, photo). Yesterday, a local professional reported snowpack collapsing near 9000' in the central Smoky Mountains. Given the recent avalanche activity and continued "red flag" signs of instability, we're not out of the woods yet. 

  You are most likely to trigger a persistent slab avalanche on shadier, very steep slopes where the wind has built a stiffer, denser slab. Recent wind-loading is most pronounced near and above about 9000' in elevation. 

  You can significantly reduce the odds of triggering a large slab avalanche by sticking to slopes less than about 35 degrees that are typically sheltered from the wind. 

  ADDITIONAL DISCUSSION: Small, isolated wind slabs formed over the weekend. While thin and relatively narrow, they may be large enough to knock you off your feet or sled. Think about the consequences of being caught and carried by a small avalanche before committing to serious or extreme terrain. 

  

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Likely

  Größe

  1–1.5

  The threat of natural and human-triggered wet avalanches will rise during the day. We should consider a couple of specific wet loose avalanche scenarios:

  • Thin, surficial slides: Small, thin slides are likely in very steep, rocky terrain that is sheltered from the wind and directly faces the sun. I saw a few of these events yesterday afternoon (view observation). This hazard will follow the sun around the compass, beginning on E-SE aspects this morning, moving to S-facing slopes by noon, and impacting W-SW aspects this afternoon and evening. 
  • Larger, "gouging" slides taking out much of the snowpack: Where the snowpack is less than about 2 feet thick, some slides could involve the entire snowpack. These are most likely on very steep, rocky slopes that are sheltered from the wind. The video to the right/below shows how powerful these avalanches can be. Imagine trying to escape that gloppy mess while it's flowing!

  Wet snow stability can change rapidly; think minutes rather than hours. The steep slope that you safely traveled on or beneath in the morning may not be stable later in the day. With last night's weak freeze and today's hot, sunny conditions, crusts could break down quickly. If you're sinking more than a few inches into a wet snowpack that resembles the oatmeal you ate for breakfast, you'll want to stay off of and out from underneath steep slopes. Pay attention to the terrain above you in your travels, and do not linger below very steep slopes longer than needed; wet avalanches frequently release on their own. Plan your day carefully to avoid traveling in or above terrain traps, especially during the afternoon.