Mount Shasta

Problemas de aludes

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilidad

  Possible

  Tamaño

  1–1.5

  Warm temperatures and sun will weaken new and old snow surfaces today, especially on solar aspects. While decreasing in likelihood, wet loose avalanches remain a concern on all aspects near and below treeline, particularly in the west half of the zone where near treeline elevations extend lower than on Mount Shasta. In the last 24 hours, Castle Lake has seen lows in the upper 30s and highs in the upper 40s. Warm temperatures are expected again today. Two days ago, a natural cornice collapse and a wet loose avalanche were noted off Middle Peak. On Mount Shasta, rollerballs and at least one point release were observed in areas near and above treeline yesterday.

  It will be important to watch for signs of instability, including rollerballs, pinwheels, point releases and boot penetration past your ankles in wet surface snow. If they become apparent, consider moving to more supportable surfaces or gentler terrain. In addition, minimize your time spent beneath corniced slopes and give them a wide berth when traveling above them.

  

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilidad

  Possible

  Tamaño

  1–1.5

  Several inches of new snow that fell between Feb 28 and March 1 combined with variable winds have created small pockets of wind slabs in the alpine. These drifts were reactive in snowpack tests yesterday and will most likely be found in steep terrain directly below ridgelines, rollovers, and rock outcrops. Pay attention to signs for where they previously formed, including slopes beneath wind lips and changes in surface texture and boot penetration. Shooting cracks underfoot or machine on test slopes indicate instability. Even small avalanches in large terrain can have severe consequences. While the problem is largely confined to areas above treeline, watch for more isolated exceptions near treeline. 

  

• 

  Wet Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilidad

  Unlikely

  Tamaño

  2–2.5

  While unlikely, there remains a remote potential for avalanches to release on the February 14th graupel/crust layer. This layer is buried two to three feet deep and was responsible for the large Old Ski Bowl Avalanche that occurred last week. Recent observations from Mount Shasta show this graupel/crust combination is absent on northerly aspects, but present on the south half of the compass. These solar aspects are also where recent meltwater has percolated and pooled on this layer, potentially causing future instability. Since the primary concern is meltwater weakening the graupel to the point of failure, we have transitioned the Persistent Slab problem to a Wet Slab problem. It is unlikely that a human or machine could trigger this layer. Consider giving steep solar aspects near and above treeline more time to settle and adjust to the recent meltwater.