West Slopes North

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

  1–2

  730 AM Update:  Winds were stronger overnight and may have built shallow wind slabs down to middle elevations.  

  N-NE winds continued to transport snow at upper elevations Tuesday, with snow streaming off the upper third of Mt Baker proper and Shuksan, and likely affected higher terrain near and north of highway 542 as well.  Winds are forecast to back off late Tuesday night into Wednesday morning.   Near the Mt Baker ski area, winds were much lighter, but before we draw too many conclusions, wind loading was likely quite variable throughout the zone in this pattern. You'll need to look for signs of recent wind-transported snow at mid-elevations in more far-flung parts of the zone.  

  If significant winds continue into Wednesday morning, you'll have obvious visual clues regarding which slopes continue to be loaded. If they back down like forecast,  proceed with caution around steep open slopes at elevation.  Wind slabs may have built on unusual aspects in this pattern. Textured surfaces, scoured slopes, and fresh wind lips will help you decipher which slopes have been recently loaded.   You may see shooting cracks in firmer, wind-stiffened snow or even signs of natural avalanches that have occurred in the last 24 hours.   

  Triggering a wind slab avalanche would have consequences on its own, but you definitely don't want a smaller wind slab avalanche to step down and trigger a larger and less survivable persistent slab avalanche.  Tread carefully around big open slopes. 

  

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Unlikely

  Dimensione

  2–2.5

  A weak layer of sugary snow, often associated with a thin crust, continues to be well documented 2-4ft below the surface.  While the likelihood of triggering an avalanche at this interface has fallen off since the last stormy period, the real consequences have not. 

  You’re most likely to trigger a persistent slab in areas where the snowpack is thin (wind-stripped or near rocks), in complex terrain with steep rollovers, or on unsupported slopes. Some shadier aspects at upper elevations have lost snow over the last few days as we've experienced a reverse loading pattern (N-NE winds).  This could make for unusual bedfellows, potentially thinning the snowpack in areas on what are traditionally lee slopes and changing how easily you could trigger an avalanche on this layer.  In other areas, you may need a large trigger; groups of people, cliff drops, or small wind slab avalanche to unlock deeper instabilities.    

  No recent human-triggered avalanches have been reported despite lots of weekend backcountry use. However, a collection of large crowns was spotted on Sunday just a few miles from the main Baker Backcountry core. Persistent slabs are hard to predict, especially this far from the storm cycle.  Stack the odds in your favor by avoiding complex, higher consequence terrain.