Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Sat
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Additional snow showers and wind should continue to impact the majority of the West South on Friday. Keep an eye out for areas of wind-drifted snow where you are more likely to trigger an avalanche. An increase in wet avalanche potential should accompany any periods of warmer springtime weather.

Avalanche problems

  • Wind Slabs

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

    Wind-loaded terrain should continue to be the most likely location for you to trigger an avalanche on Friday. Swirling winds in recent days easily redistributed snow and you could find these unstable pockets on a variety of aspects, including areas where you’re not used to seeing them. Fresh drifts or changes in the snow depth as you travel are good clues you can use to help identify wind-loaded areas to avoid. With continued snow and wind trickling in, slabs could be hidden just out of sight below the surface. If you suspect a slope to be wind-loaded, best to avoid it by seeking out simpler terrain.

    (4/13/2022)

    Subtle clues of possible wind slabs can help you locate and avoid this potential hazard.

    Photo: Andy Harrington

Avalanche Discussion

Snow showers accompanied by some periods of gusty winds should continue around the West South on Friday. Don’t be surprised to find some periods of moderate to locally heavy showers depending on your location. Although the predicted water numbers for Friday aren’t impressive by our recent standards, each wave of precipitation will incrementally increase the amount of snow over the 4/8 crust. With low-density snow, it doesn’t take much wind to drift it into larger piles. On Thursday, we received word of a skier who triggered a small Wind Slab in extreme terrain in the Crystal Backcountry. This individual was swept around 650 feet down a rocky couloir and lost some equipment due to the slide. This is a good reminder that even small avalanches can be dangerous in consequential terrain. 

We have received anywhere from 30-50” of snow in the last week, sitting atop the 4/8 interface. The storm snow has been settling and stabilizing in recent days and is generally right-side-up, cold, and winter-like. Use this easily identifiable 4/8 layer as the baseline to focus your observations on Friday to look for the existence of any potential weak layers. You may find a few density breaks or thin sun crusts depending on what aspect you are recreating. In areas lacking a slab, you may have to manage Dry Loose avalanches on steeper slopes. We do not anticipate any avalanches breaking below the 4/8 crust at this time. 

The real question mark in our minds is when we will flip back to springtime weather with strong temperatures and sunshine. Whenever this occurs, expect the cold dry snow to weaken and produce wet loose avalanches. Although the “big warmup” doesn’t appear to be in the short-term forecast, it doesn’t take much sunshine this time of year to start producing some rollerballs and isolated loose slides. On Wednesday, NWAC forecasters at Paradise noticed temperatures warming during brief breaks in the winter weather and that a slight suncrust had formed on sunny slopes the day before. On Thursday, breaks in the clouds around the zone helped to create another surface crust on slopes that see direct sunshine. If you notice a change in the weather or snowpack toward warmer and wetter while you’re out in the mountains, you’ll know it's time to avoid steep sunny slopes.

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