Bollettino valanghe

East Slopes Central

Northwest Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Mon
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
Open full map
Non aggiornato — questo bollettino è scaduto 3 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Don’t let the sun blind your ability to identify dangerous pockets of wind-drifted snow. Any triggered avalanche has the potential to break wider and deeper than expected. So steer around pockets of snow that appear wind-drifted, especially if you see shooting cracks or hear whumping collapses. 

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2

    Strong NW winds will continue to drift new snow into thick, cohesive slabs. You’ll encounter the largest and most reactive slabs as you gain elevation into more wind exposed terrain. Some of these wind drifted slabs may be touchy and propagate widely if they rest on weak snow above a crust. Any triggered slabs have the potential to step down and be up to 2-3 ft thick in favored locations. 

    You’ll find these wind slabs on the leeward sides of ridges/saddles, below cornices, and under rock and cliff bands. You may also encounter them further down slopes than usual, like mid-slope features, due to recent strong winds. Use visual clues and look for textured surfaces, fresh cornice development, and pillow-like slabs at the surface to help you identify where the wind has been at work. Pull back and default to less exposed terrain if you notice shooting cracks under your feet or machine. 

    You may find more dangerous conditions in areas closer to Salmon Lac and the Teanaway that received greater than 6 inches of new snow. 

    (1/6/2024)

    This skier triggered avalanche occured in a wind loaded area on a NE Aspect @ 6000 ft near Blewett Pass on Saturday. This avalanche likely stepped down into old snow from December.

    SS-AS-R2-D2-O

    Photo: Max Steed

Avalanche Discussion

Observers across the region have reported endless signs of instability on Saturday. Backcountry travelers in the Blewett Pass area had a close call with a triggered avalanche that broke 1-2 ft deep and propagated widely. This large avalanche occurred on a NE aspect at 6000 ft in a wind loaded area and likely failed on old, faceted snow from December. 

Saturday's storm brought a wide array of storm totals across the zone. The southwestern parts of the zone near Salmon Lac/ Teanaway received the most with 8-10 inches. Much less was reported at weather stations further north and east.

Sunday is shaping up to be a pleasant day across the eastern cascades. As the sun pokes out, keep an eye out for rollerballs or sticky snow surfaces as these are signs that wet loose avalanches could soon follow. The forecast team doesn’t expect these to be that big or widespread, but it is worth keeping on your radar if you find yourself on solar slopes. 

The snowpack in the zone is made up of a number of potential weak layers and crusts, and the upper crust isn't the only one to consider. The Solstice crust is another layer that has produced large slab avalanches with control work at Mission Ridge on December 30th. Observers reported whumphing collapses from the west side of Jolly Peak at 6,500ft on 1/3, and from 5,000ft in the Enchantments on the 28th. Though we haven't seen many avalanches on these layers yet, we just haven't had much new snow to react as a cohesive slab yet. As slabs become more connected and we add more snow, these slightly deeper layers warrant more consideration.

The snow cover is still shallow, especially further east in the zone and at lower elevations. Expect to encounter exposed creeks, and shallowly buried logs and rocks in many areas. 

If you get out, let us know what you see by submitting a public observation!

 

Regioni coperte