Mount Shasta

Problemi valanghivi

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Possible

  Dimensione

  1

  The high winds today--50-60 MPH above treeline--will mean significant wind transport of snow. So far, the snowpack has been found to be low density and incohesive. Remember, you generally need three elements to have a slab avalanche: (1) terrain steep enough to slide, (2) a cohesive layer of snow above a weak layer, and (3) a trigger. While our snowpack so far has generally shown poor slab quality, today's new snow and wind will begin to change things. Today's wind will help break up and compact any new snow, helping to form shallow wind slabs.  While wind-loaded test slopes have so far remained unreactive, an inkling of slab formation was seen yesterday through minor cracking underfoot on leeward slopes while skinning (see image).  Weather stations on Mount Shasta have shown wind above the threshold to transport snow (7-10 MPH) over the past 72 hours from the SE-S-SW-W. Wind slabs will most likely be found on steep, unsheltered slopes near and above treeline.