Bulletin d’avalanche

Salt River and Wyoming Ranges

Bridger-Teton Avalanche Center
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Danger d’avalanche

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

Points saillants

The avalanche danger will begin at LOW and rise to MODERATE as the day warms and snow surfaces become wet. Wet snow avalanches are possible on steep, rocky slopes that face the sun. Monitor the snow surface as the day warms and consider exiting the mountains if you are sinking into slushy snow or see signs of wet avalanche activity. Terrain near or under cornices should be given a wide buffer.

Problèmes avalancheux

  • Loose Wet

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

    Wet loose avalanches are possible on steep, sunny slopes as the day warms. These avalanches begin at a point, usually the base of a warm rock or your sled, and fan out to collect snow as they move. They are most hazardous in confined terrain or on large slopes where they gather a lot of snow. Wet slab avalanches have been on the radar as melt-water has been working its way down towards deeper layers in the snowpack. Fortunately, solid overnight freezes have limited its progression making these avalanches unlikely. Steep and rocky south facing slopes are the first places that these avalanches might occur. 

    It is important to monitor the snow surface as the day heats up. Surface crusts formed overnight can break down quickly in areas that experienced a light freeze. Consider changing your plans, or exiting the mountains, if the snow surface becomes slushy and you are sinking in past your ankles. Roller balls and small point releases are also signs that conditions are becoming unstable.

    (3/17/2024)

    Wet loose activity on the southeast face of Ferry Peak.

    9,200'

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–3

    Weak snow that formed in December persists at the base of the snowpack across the entire Greys River forecast zone. However, the thickness of the hard slabs that overlay this weak snow varies based on geographic location. In the middle and upper elevations of the Salt, Snake River, and deeper portions of the Wyoming Range, these weak layers are buried 3-5+ feet deep making it difficult for a human to impact them. In shallow parts of the forecast zone, such as the far eastern side of the Wyoming Range, these slabs are only 2-3 feet thick making it possible for humans to trigger avalanches on the buried weak layers. Shallow, rocky, and unsupported terrain on the north half of the compass is where this problem has been most active. Keep in mind that a large trigger such as a cornice fall could trigger one of these very large avalanches, even in areas where the snowpack is deep.

    Careful snowpack evaluation is required in the Greys River zone due to variable snow depths. Probing or digging can provide useful information about the depth to the weak layers preserved at the bottom of the snowpack. This evaluation is critical if you are riding in a shallow part of the zone. A total snow depth less than 6 feet (200cm) is a red flag.

    The last reported human triggered avalanche involving deeply buried weak layers occurred on March 9th on the far eastern side of the Wyoming Range.

    (3/8/2024)

    A very large persistent slab avalanche that failed during the early March storm cycle. This type of terrain is where this problem is most active. Very steep, unsupported slopes near cliffs. Note the heavily corniced ridgeline above.

Avalanche Discussion

Another classic spring day is in store for today. Overnight lows were slightly cooler than yesterday. Upper elevations dipped below freezing at 7pm and dropped to 25 degF by 5am. Mid elevations experienced a lighter freeze with stations dipping below freezing at 9pm and dropping to 28 degF by 5am. Again, day time highs are expected to reach near 40 degrees at 10,000’ and skies are forecasted to be clear.

Limited wet avalanche activity was observed yesterday afternoon. Most activity was small and confined to steep south facing slopes near rocks and cliff bands. This is most likely due to the adequate overnight freezes that we have experienced during this spell of high pressure. Still, it is important to get out early and return early. Ideally, you won’t see any signs of instability if your timing is right. Exiting the mountains by noon appears to be a good rule of thumb for the current conditions. Monitor the snow surface, keep overhead hazards in mind, and be prepared to adjust your plans if the snow becomes too wet or you begin to see signs of wet avalanche activity. Enjoy the spring riding!

Régions couvertes