Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Tue
Alpine
1 · Low
Treeline
1 · Low
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Out of date — this forecast expired 4 years ago.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

Avalanches are unlikely today. Make a plan with good safety margins and pay attention to the weather, snow, and terrain. Use what you see to change plans if needed.

Avalanche Discussion

Normal caution

Since the last storm, the snowpack has consolidated and grown stronger below the surface. Even though the old, weak layers still exist in the snowpack, avalanche activity has become unlikely as those weaknesses have become unreactive. The snow surface has also gotten more variable since the last storm. Some of the surface snow has gotten weaker, especially on northerly aspects. 

Building and maintaining good backcountry travel habits remains important, even during LOW avalanche danger. Talk with your partners to plan routes that match the terrain to the group's skills and goals. As you travel, pay attention to your surroundings, and keep looking for any isolated signs of instability. When traveling in avalanche terrain, travel through it one at a time. Then, regroup in safe areas out of avalanche run-out zones. Practicing these techniques will help solidify them for when the avalanche danger increases again. Review the day with the group to discuss what you saw and how your plans worked out. These quick end-of-the-day debriefs can provide excellent learning opportunities. 

Recent Observations:

  • At least a foot of storm snow settlement has occurred since Dec 12.
  • Surface hoar is widespread. Light snow on either Tuesday or Friday could bury it. This is worth keeping an eye on during the 24 hours before any snowfall events.
  • Moderate winds from the E and SW over the past few days have scoured snow near and above treeline but have not moved enough snow to form new wind slabs.
  • Thin sun crusts have formed on the snow surface in many areas of direct sun exposure, mainly on E-SE-S-SW aspects.
  • The faceted snow near the bottom of the snowpack that made up the Dec 1 persistent weak layer (PWL) and the Dec 8 buried surface hoar layer contributed to an impressive avalanche cycle from Dec 1 to Dec 12. Since Dec 12, we have received no additional reports of new avalanches on these layers and almost no reports of other signs of instability. The Dec 1 PWL is now buried some 4 to 6+ feet deep in the snowpack. Recent snowpit data has shown a trend of little to no reactivity on either of these weak layers, along with increasing strength.

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