Bollettino valanghe

East Slopes South

Northwest Avalanche Center
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Pericolo valanghe

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

In sintesi

Where new snow previously fell, you could encounter small slabs of wind-transported snow. If you plan to recreate in exposed and complex terrain near the Cascade Crest, investigate for instability where the snow is uneven and textured or where cornices have developed. Shooting cracks, collapsing, and recent slab avalanches are good reasons to pull back into more sheltered terrain.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    This problem will be most apparent in areas that received new snow Sunday night into Monday, namely, areas along the Cascade Crest, such as Bumping Lake which received 4". The zone may see another inch or two throughout the day, which would add to older slabs. Slabs will be the more sensitive on the northern end of the aspect dial and at upper elevations. Hazard is probably low in areas further east, but a larger storm moves through in the 2-5 pm time frame on Tuesday that could begin changing conditions before the day ends.

    Wind slabs typically form just below ridgelines and on exposed convexities and gullies. Visual clues such as rippled snow surfaces, sharp drifts, and dunes will help you identify where the wind has transported snow. Another dusting may obscure some of these surfaces but blowing snow will help point the way if that's the case. Although unlikely to bury you, a small avalanche could knock you over and take you for an unenjoyable ride.

    (3/1/2025)

    A wind slab avalanche on Alta Vista. This one likely failed earlier this week on 2/25-2/26.

    Photo: Andy Harrington

Avalanche Discussion

More hazardous avalanche conditions are regulated to rather specific areas, and any new slabs should be small. All in all, it will probably feel like a pretty safe day on Tuesday. Still, it just isn't "Low" out there where new snow fell. The elevated hazard lies in a few considerations. Many slabs could have formed over crusts which slabs will be having trouble bonding to. Furthermore, crusts often act as slick sliding surfaces, so this specific wind slab problem could be taking longer to heal. These crusts will also be slippery for you should you trigger an avalanche and get knocked over. Other variable surfaces were previously observed prior to new snow, including surface hoar and faceted snow, which could also be problem layers. Ultimately, just take a bit of time to investigate the slope you plan to ski or ride and consider the consequences before diving in.

The sun might poke through the clouds on Tuesday morning. Any new dry snow infiltrated by sunshine will rapidly warm and destabilize. Be on the lookout for moistening, sticky snow surfaces and the increased potential for a small wet loose avalanche. 

An NWAC Forecaster traveled into the Manastash Ridge area on Sunday. She reported variable, shallow travel at lower elevations with improving coverage starting around 4500 ft. Northerly aspects harbored 2-3 inches of lightly faceted snow and some isolated pockets of stubborn wind slab. Solar aspects had a more robust crust that struggled to soften due to the strong winds and cloud coverage. Check out her full observation here.

Submit an observation to help NWAC Forecasters reduce uncertainty. It can be short, simple, and even anonymous. Visit the Recent Observations page to get an idea of what backcountry travelers are sharing that helps entertain the forecasts in other zones.

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