Bollettino valanghe

East Slopes Central

Northwest Avalanche Center
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Pericolo valanghe

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

In sintesi

Another storm favoring the east slopes of the Cascades will bring snow, strong winds, and heightened avalanche hazard. You're likely to trigger large avalanches in wind-drifted snow at upper elevations, and a stout crust below the new snow will make smaller avalanches possible at lower elevations in sheltered terrain. Make conservative terrain choices while these storm systems continue to roll through. 

Problemi valanghivi

  • Wind Slabs

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

    More snow on Monday night with stronger winds will increase the size of recently formed wind slabs. Ridgelines, the base of cliffs, and steep gullies are prime locations to trigger one of these avalanches. Avoid steep lee slopes with deep drifts and expect increasing hazard as you gain elevation. At lower elevations, you could trigger smaller storm slabs or wet avalanches that run farther than expected on the Solstice Crust. Even a small avalanche could cause injuries that ruin your season, so choose more conservative terrain while we make our way through this holiday parade of storms. 

    Pay attention to blowing snow and rippled, textured surfaces as clues of recent loading. You can use small test slopes or hand pits to gauge how reactive these slabs are. Cracks shooting out from under your feet or machine are obvious signs that you may have found an unstable wind slab.

    (12/23/2024)

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

Avalanche Discussion

A similar storm will begin impacting the eastern Cascades on Monday night, with precipitation likely starting before midnight in the Wenatchee Mountains. This southeasterly storm track will favor areas like Mission Ridge, Icicle Creek, and the Teanaway. Storm totals will still be modest, in the 5-7 inch range, but the strong winds will significantly affect where the snow actually ends up by Tuesday morning. Expect the highest avalanche hazard in the first half of the day as precipitation and winds taper off on Tuesday morning. 

On Monday, observers in the Icicle Creek area reported that travel conditions up to 5200ft were challenging, with more pleasant conditions above that. Westerly aspects at upper elevations only have a 2-3 ft deep snowpack, while northern aspects hold 3-4 ft and significantly better soft snow travel conditions. They found reactive wind slabs 6-8 inches deep on lee slopes below the ridgeline. Another notable observation was that at 6400ft, there was not a stout melt-freeze crust, indicating that these upper elevations never saw the rain that formed the Solstice Crust. At 6000ft, the Solstice Crust is buried 5 inches deep.  

The 12/7 crust likely won’t be an issue in most middle and lower elevations moving forward. However, higher elevations that escaped the recent rain 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 (NE, 6400 ft). While this is only one data point in the zone, it's worth keeping on your radar if you venture to higher-elevation terrain. 

Let us know what you see by submitting a public observation. 

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