Avalanche forecast

East Slopes South

Northwest Avalanche Center
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Avalanche danger

Fri
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

New snow and increasing wind speeds will build reactive slabs of wind-drifted snow. Steer around steep slopes that are being actively loaded or show signs of recent loading.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Winds will change more easterly which will start drifting new low density snow into reactive slabs. You may find these slabs forming in usual spots such as west facing slopes or cross-loading terrain features.

    Recent new snow and heavy drifting have created slabs 1-2 ft thick at mid and upper elevations. Cold temperatures and continued drifting  will help keep these slabs fresh and sensitive to your weight on Thursday. You’ll find these slabs forming on the leeward side of ridges, under cornices, in gullies/couloirs, and cross-loading alpine features. As you travel use visual clues to help you identify slopes of concern. Look for blowing snow, cornice growth, ripples, or rounded pillows at the snow surface to identify where the wind has been at work. If you see shooting cracks under your skis/sled or feel wind-stiffened snow, be ready to take a big step back and avoid nearby steep slopes. 

    (12/3/2022)

    Actively blowing snow, freshly building sharp cornices, and textured surfaces. All easy-to-identify signs of wind-loading. Look for slabs to develop on the slopes on the left side of the picture.

    Photo: Dallas Glass

Avalanche Discussion

The East-South snotel sites have picked up anywhere from 3-6 inches of low density snowfall. You may find higher amounts closer to the Cascade Crest, and more specifically close to White Pass, that did fairly well with this last system. The main story was the radical wind speeds, with Sedge Ridge reporting gusts exceeding 60 mph out of the WNW during the early hours of day. These wind speeds velocities have likely created slabs in many unusual locations, such as further down slope than usual or well below treeline. So, keep an eye out for these at all elevations and aspects as you travel through the terrain. 

As we move out of this stormier regime the big question mark will be how the new load bonds with the old snow surface.  Leading up to this storm, observers have reported weak, faceting snow on northerly aspects.  So as new snow piles up, be sure to check how its bonding with the old snow interface. Use small test slopes or snowpack tests to gauge how easily the new snow fails. 

These next few days are going to be down-right cold as a cold upper trough parks over the western US. So be prepared with extra warm layers and consider the consequence of something going wrong during frigid temperatures like this. 

On Friday an observer in the American Ridge area reported finding good cold snow on east facing terrain, faceting snow in the shade,  and a sun crust on solar slopes that extended up to ridgetop.  At higher elevations they noticed winds drifting any remaining soft snow. Check out their full observation here. 

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

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