Bollettino valanghe

East Slopes Central

Northwest Avalanche Center
Vedi sulla mappa

Pericolo valanghe

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

In sintesi

Merry Christmas to those who celebrate! Use caution on slopes steeper than 35 degrees if you find wind-loaded slopes. Blowing snow and cracks shooting from your skis or sled indicate instability. Dial back your terrain choices as conditions begin to change with a large storm system rolling through late Wednesday afternoon.

Problemi valanghivi

  • Wind Slabs

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

    Increments of snow accompanied by wind keep wind slabs on the table. The east side of the Cascades should receive 2-5 inches of new snow predominantly near the Cascade Crest on Christmas Day. New slabs will build on top of lingering older slabs and you could trigger a large avalanche in these areas. A small avalanche could knock you off your feet and carry you into rocks or over cliffs.

    Look for blowing snow, indicating fresh wind slab formation is occurring on lee slopes. Cornice development will be a better visual clue for where older wind slabs might be lingering as rippled, uneven snow surfaces from previous wind transport may be obscured from view. Hop on a small, low angle test slope representative of the slope you plan to ski or sled to check for cracking and collapsing. If you see signs of instability, stick to lower angle, wind-sheltered slopes.

    (12/23/2024)

    Shooting cracks in recently wind drifted snow in the Icicle Creek Drainage on Monday (Dec. 23)

Avalanche Discussion

It’s the most wind-erful time of the year but Christmas Day will ultimately be the calm before the storm. A bigger system will begin impacting the east side of the Cascades on Wednesday afternoon. If you are out on Wednesday, don’t anticipate similar conditions on Thursday. Avalanche hazard will have increased significantly if the storm pans out the way it’s forecasted to. “Yule” be sorry if you don’t read the avalanche forecast for more details before you head out.

On Monday, observers found reactive wind slabs 6-8 inches deep on lee slopes below a ridgeline. Warm temperatures have likely aided in healing slabs but there is uncertainty if this is definitively the case in widespread areas. As new snow builds on top and adds load, the potential to trigger an older wind slab remains. 

The 12/7 crust likely won’t be an issue in most middle and lower elevations moving forward. Higher elevations that escaped the recent rain and warming event may still harbor weak snow adjacent to this crust. On Saturday, the Mission Ridge Pro Patrol reported propagating test results on faceted grains beneath the 12/7 crust. A hand pit is a quick and easy way to look for both slab/crust combos and poor snowpack structure (harder over softer snow).

Help NWAC forecasters reduce uncertainty by submitting an observation!

Regioni coperte