Bulletin d’avalanche

East Slopes South

Northwest Avalanche Center
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Danger d’avalanche

Fri
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Périmé — ce bulletin a expiré 3 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

New snow and increasing wind speeds will help build pockets of wind drifted snow all over the compass. Use visual clues such as blowing snow or wind textured surfaces to help you identify slopes of concern. Default to more sheltered terrain out of the wind zone to avoid this avalanche problem. 

 

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    An uptick in southeast winds should start drifting new snow into soft wind drifted slabs. Nothing good usually comes out of these upslope winds, so keep an eye out for these slabs to be forming in some weird spots such as west aspects or cross-loading terrain features. 

    East and west winds have been at work drifting new snow this past week, so you may find these slabs all over the compass. As you move through the mountains look for blowing snow, fresh cornices, and pillow-like slabs at the snow surface to help you identify possible slopes of concern.  You can use small test slopes with your sled or skis to guage how sensitive these slabs are to your weight. Keep your terrain selction simple if you notice signs of unstable snow such as shooting cracks or hear snow that sounds hollow like a drum. 

    (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 continues to be in a favorable pattern and over-produced in the last 24 hours. Snotel sites across the zone picked up an additional 4-6 inches of new snow on Wednesday, with the most accumulating in the Green Lake area. 

The trickle continues into Thursday and really starts packing a punch Thursday afternoon/evening. So if you’re out during the later hours of the day, you may encounter more dangerous conditions. Keep an eye out for those simple signs such as blowing snow or heavy precipitation rates to help guide your travel decisions. 

A generally strong snowpack exists throughout the East South, and the recent storms have been improving winter recreation opportunities significantly. However, the recent snow has piled up on various crusts. While we have not seen any avalanche activity on deeper, older snow layers, we are tracking these interfaces with the additional loading events.

Katie traveled to the Ahtanum Meadows area on Tuesday. She found 7-12 inches of new snow and excellent riding conditions. Snowpack test yielded unremarkable results. However, there was some weak snow below the Valentine's Crust, now about 2 ft below the snow surface. You can check out her observation here for more details. Before the storm cycle on the 25th, I traveled into the American Ridge area near Bumping Lake and observed slick surfaces at lower elevations, dry faceting snow at upper elevations in the shade, and a thin sun crust on slopes with a southern tilt (observation).  

Régions couvertes