Bulletin d’avalanche

Ogden

Utah Avalanche Center
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Danger d’avalanche

  • Alpin
  • Limite forestière
  • Sous la limite forestière
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Périmé — ce bulletin a expiré 8 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Dangerous avalanche conditions - the avalanche danger is CONSIDERABLE on all steep low, mid and upper elevation slopes for triggering slabs of wind-drifted snow, which can be found on all aspects. CONSIDERABLE means human triggered slides are likely, and natural avalanche possible. Avalanches breaking on faceted weak layers can be triggered from a distance or below, especially on wind loaded slopes. Wet loose sluffs are possible on steep, sunny slopes as temperatures warm today.

Careful snowpack evaluation, cautious route finding and conservative decision making are essential for backcountry travel today. Low angle, wind sheltered terrain is the place to go.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    2

    Yesterday’s winds were drifting snow at all elevations and on all aspects - high ridge lines, mid elevations bowls and subridges and even into the low elevations. Avoid the dense and cakey slabs of wind drifted snow on steep slopes and watch for these drifts in unusual spots at the mid and lower elevations. These drifts may be even more stubborn today, wanting to break above you. Instead, head for very wind sheltered terrain.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    3

    It has gotten more complicated - there is weak, sugary faceted snow mid snowpack in the Ogden area mountains. The weak snow formed on the surface before the last storm, and is now buried beneath the new 2 to 3 feet of snow. This snow is at mid and low elevations, in addition to upper elevations. You are most likely to trigger a slide on one of the mid-pack faceted weak layers on a wind drifted slope. Slides breaking on sugary facets can be remotely triggered from a distance. I would expect to trigger some of these slides on "unusual micro terrain features" at the low elevations, including terrain traps like small gullies.

  • Loose Wet

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

    Today’s wild card - much warmer temperatures and the possibility of direct sun are in today’s forecast. This combination may heat the snow surface on steep sunny slopes, and wet loose sluffs will become possible. Look for telltale signs of heating snow - the snow becoming heavy, damp or sticky, roller balls or small wet loose sluffs starting to run. This means it’s time to get off of and out from under the steep sunny slopes that are heating.

Recent Activity

In the backcountry, there was widespread collapsing and cracking with small test slopes releasing in the new snow. At the resorts, widespread new snow avalanches were reported, especially in wind drifted terrain. These were naturals and slides released with explosives and ski cuts. Some were stubborn, some were in unusual spots. These slides were easily large enough to bury a person.

Observations by Mark Staples and Brian Smith.

Brian Smith releasing a "test" slope - note it's very small and he has a spotter watching him.

Snow and Weather

Whew! It’s been a wild 48 hours of snow and wind.

Ogden area mountains - 2 to 3 feet of snow, 2 to 3 inches of water, with as much as 5” of water at the Ben Lomond Snotel

  • Significant southwest winds on Monday: Ridgeline speeds were strong in the Ogden area mountains, averaging 45 to 55 mph, with gusts in 70s. 15 to 25 mph average speeds, with gusts in the 40s, occurred at the mid and low elevations, too.
  • This morning, under partly cloudy skies, temperatures are in the mid to upper 20s and forecast to warm dramatically into the mid to upper 30s at the mid elevations today. Winds are from the northwest, averaging 5 to 10 mph, with the highest peaks averaging 15 - 20 mph. The snow is “upside down” - denser and wind blown snow is sitting on top of light density snow. So trail breaking is tough and turns punchy - settlement will hopefully improve conditions.

General Announcements

This information does not apply to developed ski areas or highways where avalanche control is normally done. This forecast is from the U.S.D.A. Forest Service, which is solely responsible for its content. This forecast describes general avalanche conditions and local variations always occur.

Régions couvertes