West Slopes North

Problemas de aludes

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alta montaña
  • Límite del bosque
  • Bajo el límite del bosque

  Probabilidad

  Likely

  Tamaño

  1–2.5

  Several feet of new snow and moderate to strong winds have created a patchwork of drifting patterns and shallow instabilities. For reference, the Heather Meadows weather station recorded ~3.8 inches water / ~44 inches of snow in the last three days. 

  There was a natural avalanche cycle late Sunday night or early Monday morning, and on Tuesday we received several reports of smaller natural and human triggered avalanches in wind affected snow.  These more recent wind slabs were soft, 6-10 inches deep, and in the D1-D2 range. Some were ‘stubborn', or hard to trigger, and some were fairly ‘touchy’, or easy to trigger. Almost all of the reports are from lower and mid elevations (probably because conditions are keeping people out of the upper elevations) and it's likely that upper elevation slabs are larger, more unpredictable, and more dangerous. 

  So far we have no reports of larger avalanches in the storm snow, but take that for what it is worth – visibility was mostly poor over the last two days. 

  There is some uncertainty (especially in the alpine) around the distribution, sensitivity, and size of these wind slabs. It's a good idea to avoid steep, wind loaded terrain – especially if the runout is consequential. 

  

• 

  Deep Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alta montaña
  • Límite del bosque
  • Bajo el límite del bosque

  Probabilidad

  Possible

  Tamaño

  2–3

  Two explosive triggered avalanches and two natural avalanches were triggered deep in the snowpack on the Shuksan Arm over the last week or so. Check out one of these avalanches HERE. All of these avalanches occurred on steep, unsupported alpine terrain features.  

  The layer in question seems to be a layer of surface hoar which was buried prior to Christmas. We’ve had several storms since then and at this point the layer is probably between 4 and 7 feet deep. Although we don’t have any reports of big avalanches occurring on this layer as a result of the recent storm load, visibility has been poor and information sparse.

  The take-home is that an even small possibility of very large avalanches triggered deep in the snowpack is another reason to steer clear of large, wind-loaded slopes and their run-out zones.