Bulletin d’avalanche

Logan

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 7 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Heightened avalanche conditions and MODERATE danger exist in the backcountry. People could trigger avalanches in drifted upper elevation terrain and on steep sunny slopes with saturated snow. The snow is stable and the danger LOW on most other slopes in the Logan Zone.

  • Evaluate snow and terrain carefully.

Problèmes avalancheux

  • Wind Slabs

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

    Several inches new snow fell this week on upper elevation slopes, and westerly winds were plenty strong enough to move it around. West winds increased again overnight, cranking out hourly average wind speeds of around 28 mph at the CSI Logan Peak weather station. This week's drifts and large cornices were sensitive to human triggering, but they will likely be stiffer and more stubborn today. Harder wind slabs sometimes allow people to get out on them before releasing.

    • Watch for and avoid stiffer drifted snow near ridge lines and in and around terrain features like cliff bands, scoops, gully walls, and sub-ridges.

    • Avoid ridge top cornices, which can break much further back than expected and start avalanches on slopes below.

    There were a few large natural cornice falls due to drifting from west winds this week.

  • Loose Wet

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

    Rapid warming today will cause heightened wet avalanche conditions, especially on sunny slopes. Roller balls, pinwheels, and surface sluffs are all signs of increasing wet snow instability. Natural loose wet avalanches may become possible in the the afternoon.

    • Avoid travel on and below steep sunny slopes with saturated snow.

Recent Activity

We found easily triggered and manageable soft wind slabs and cornice falls this week on drifted upper elevation slopes. West winds increased significantly again early this morning and today's drifts will be stiffer, deeper, and perhaps a bit less manageable.

Thursday, we noticed a recent avalanche of wind drifted snow, triggered by a sizable cornice fall off Red Pine Ridge that ran at least 500 vrt' into Richard's Hollow. And, we have reports of a large natural cornice fall avalanche from midweek on Cornice Ridge.

Snow and Weather

It's 28°F at the 8400' Tony Grove Snotel this morning, and there is 78 inches of total snow, containing 120% of normal Snow Water Equivalent. West winds picked up again early this morning and are currently blowing around 30 mph at the CSI Logan Peak weather station, and it's 23°F at 9700'.

Several inches of fresh snow fell at upper elevations this week, and shallow powder conditions are really nice, especially in sheltered terrain. Drifting from west winds has created heightened avalanche conditions in exposed upper elevation terrain, and rapid warming today will cause potential for wet avalanches on sunny slopes.

We observed a thin rime-crust and heavily rimed trees above about 8000' in open terrain on windward slopes in upper Providence Canyon Thursday.

The National Weather Service has issued a Winter Storm Watch for a widespread area, as a strong and cold storm will impact the area Sunday night through Monday. We'll see mostly sunny skies today, with 8500' high temperatures expected to climb to around 40°F, with 16 to 18 mph west-southwest winds. Increasing clouds are expected tonight, with low temperatures around 27°F, and 18 to 21 mph southwest winds. Snow showers are possible tomorrow afternoon and it will be cloudy, with a high temperature near 37°F, and 16 to 20 mph west-southwest wind. The strong and cold storm is expected to arrive late Sunday, with 9 to 15 inches of new snow possible at upper elevations by Monday afternoon.

Additional Info

Although increasingly unlikely, dangerous human triggered avalanches failing on a deeply buried persistent weak layer remain possible on isolated upper elevation slopes. Some avalanches might step down into buried persistent weak layers, involve large volumes of snow, and be quite dangerous and destructive. Tuesday, we found very poor snow structure on slopes with shallow snow on the west side of the south ridge of Beaver Mountain. Our stability tests showed potential for avalanches failing on sugary faceted snow buried by the New Years storm.

We triggered several shallow avalanches of wind drifted snow and cornice falls in the backcountry on the south ridge of Beaver Mt. earlier in the week.

We noticed a few large fresh roof avalanches off metal barn roofs in the Bear Lake Area last week. Many are still holding lots of heavy snow, and gradual melting is causing them to drip and creep. It could get quite warm today, increasing the possibility of large roof avalanches, so keep and eye on the kids, animals, and vehicles.

General Announcements

Are you looking to improve your avalanche skills? We are offering a Backcountry 101: Introduction to Avalanches class at Powder Mountain February 14-15. Info and sign up HERE

The anual CROWBAR backcountry ski race will be on Saturday, February 8. The unique and classic backcountry race will be held at the Swan Flat/Garden City Trailhead in upper Logan Canyon. There are four divisions (Junior, Recreation, Heavy Metal & Race) with different climbs, descents, and technical booters. Participants must carry avalanche rescue gear (beacon, shovel, probe) and can use alpine touring gear, telemark skis, or splitboards. Register on UltraSignup, or sign up to volunteer at this year's race!

Thanks to the generous support of our Utah ski resorts and Ski Utah, we have discount lift tickets available. All proceeds from these go towards paying for avalanche forecasting and education! Get your tickets HERE.

EMAIL ADVISORY. If you would like to get the daily advisory by email you subscribe HERE.

Remember your information can save lives. If you see anything we should know about, please help us out by submitting snow and avalanche observations....HERE. You can also call us at 801-524-5304, email by clicking HERE, or include #utavy in your tweet or Instagram.

This forecast is from the USDA Forest Service, which is solely responsible for its content. The forecast describes general avalanche conditions and local variations always occur.

I will update this forecast before about 7:30 tomorrow morning.

Régions couvertes