Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
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In sintesi

Generally safe avalanche conditions should exist throughout the Snoqualmie Pass zone on Saturday. This doesn’t mean that avalanche danger is non-existent, so make your own observations and take note of how the weather and snowpack are changing throughout the day. These changes could lead to an increase in the potential for avalanches.

Problemi valanghivi

  • Loose Wet

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    Probabilità
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    1

    High freezing levels could combine with periods of sunshine or rain to trigger some lingering Wet Loose avalanches on Saturday. The more likely scenario will be that the snow becomes “ripe” enough from these environmental inputs that you will be able to push snow on steep slopes to create Wet Loose avalanches of your own. Regardless of you or nature being the trigger, these slides will be more likely on steep slopes if they are to materialize. Slopes that receive direct sunshine have been the primary target for these slides recently, but if we receive some light rain, slopes on all aspects will be susceptible to creating Wet Loose slides.

    These slides are often trivialized, but they can entrain lots of snow as they descend and can be consequential if they sweep you off your feet near terrain traps. If you notice that the surface is sticky and wet or you are sinking into wet snow deeper than your ankle, then it's time to head toward lower angled or shaded slopes. When choosing travel routes, keep aware of terrain and other humans above you capable of shedding snow into your location. 

    (4/1/2021) Small natural loose wet avalanches on Kendall Peak. These slides likely occurred 3/30-31. SW 5400'

Avalanche Discussion

The upper snowpack around Snoqualmie Pass has taken a beating over the past week, with multiple melt-freeze cycles and plenty of high freezing levels and sunshine. Saturday should be another fairly warm day with freezing levels reaching 7000 feet, but there should be a bit less sunshine than we have seen recently and possibly a poor overnight freeze. The cloudy weather should help to limit Wet Loose avalanches and produce generally safe avalanche conditions. As we often like to remind you, low danger doesn’t mean no danger, and we have a few things for you to keep in mind:

  • There is a possibility of some light rain developing at the pass before day’s end. If this comes to fruition, look for Wet Loose avalanches, particularly on northerly slopes that may still be holding onto some colder and drier snow. Periods of prolonged sunshine will be the most likely time for Wet Loose avalanches to develop if there is no rain.
  • While we still have our eye on some layers in the upper snowpack in isolated areas, our concerns on Saturday are focused on the surface snow. We are including wind drifted areas in isolated high elevation terrain and cornices in our categorization of surface snow. Give cornices a wide berth by not traveling on or beneath them. They notoriously break back further than expected and often fail during periods of warmer weather.
  • Glide cracks have continued to open up or widen around the zone. Warm temperatures and liquid precipitation will only enhance the possibility of these slides failing. Choose travel routes that put plenty of distance between yourself and these unpredictable slopes.
  • The snowpack has not yet undergone its full transition into a springtime snowpack. Not far below the surface, you can still find cold dry snow that could be entrained or fail as a slab given the right avalanche.

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

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