Bulletin d’avalanche

West 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 5 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

As the storm winds down and some flurries start to fall at upper elevations, don’t forget about all the recent rain and very large avalanches. Give big slopes and cornices a wide berth as you determine how the snowpack has changed over the past week. If you are at Paradise, take an even bigger step back and give the snowpack plenty of time to heal.

Problèmes avalancheux

  • Loose Wet

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

    The snowpack is still in a period of adjustment after multiple days of rain throughout the zone. On Thursday, you should continue to think about wet avalanches anywhere you find unconsolidated wet snow on or near the surface. This includes above the rain/snow line. Wet snow may be more difficult to initiate a slide in, but once it gets moving it can grow large and destructive as it moves downhill. We expect most slides to be loose and initiate on steeper features over 35 degrees. However, if you find that slides are breaking off as a cohesive slab, be sure to dial it way back. Wet Slabs are not a problem you want to mess with. 

    (1/12/2022)

    Wet avalanches were observed by NPS rangers coming from high on Mount Rainier. Unseasonably warm temperatures allowed rain to extend to the highest peaks in our region.

    Photo: NPS Rangers

Avalanche Discussion

Thursday should be the final day of a multi-day storm that delivered rain to the summits of the highest peaks of the Cascades. As of Wednesday afternoon, areas near the crest received approximately 1 inch of rain during the cycle. The real story was Paradise, where a staggering 5.37 inches of rain were recorded since Monday night! On Wednesday, Mt. Rainier rangers reported plenty of wet avalanche activity, some of which came from high up on the mountain and grew very large. Over near Crystal Mountain, both recreationalists and the patrol reported small Wet Loose avalanches. Wet snow avalanches can occur long after the rain has stopped, so we are not out of the woods by any means.

The extent of this avalanche cycle is not yet known, but it is the second major loading event and avalanche cycle within the past week (January 6-7 being the first). Throughout this time period, the snowpack has undergone a significant transformation and has been under a lot of stress. Very large avalanches have been reported across the zone and should have your attention. Uncertainty surrounds these slides and we continue to be concerned about the potential for more of them as rainwater makes its way through the snowpack. Cornice failures, Glides, Wet Slabs - these massive slides are unpredictable and you can’t outthink or manage them, you can only stay out of their way. Be patient and give the snowpack a bit more time to adjust before stepping into big slide paths or alpine terrain. If you are traveling near Paradise, you may want to step back even further and treat Thursday as Considerable due to the ridiculous amount of rain they just received.

At upper elevations, don’t be surprised to see some snow falling as temperatures start to cool. We expect any snow to bond well to the wet snow surface and do not expect there to be enough accumulation to drive much of an avalanche hazard. But with some strong winds in the forecast, you could run into an unstable pocket of wind-drifted snow in isolated areas to steer around.

Régions couvertes