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 of wind drifted snow on upper and some mid elevation slopes. Wet avalanches are possible on steep lower elevation slopes with melt-softened saturated snow.

  • Evaluate snow and terrain carefully.

Problèmes avalancheux

  • Wind Slabs

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

    Several inches of heavy snow fell yesterday on upper elevation slopes, and westerly winds were plenty strong enough to move it around. Northwest winds last night continued to drift the snow, picking it up in the flats and on windward slopes or fetch areas and dropping it into lee slope deposition areas and avalanche starting zones. Yesterday's drifts were quite sensitive to human triggering, but they will 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.

  • Loose Wet

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

    Overnight temperatures at low elevations stayed near freezing, and it'll warm up soon. A bit of rain fell on the snow yesterday and it's saturated and slushy. Ski pole and boot penetration is to the ground in many areas. Loose and wet slab avalanches are possible on steep lower elevation slopes with saturated snow. We triggered lots of large roller balls, roller swarms, and small sluffs at mid and lower elevations in Card Canyon Sunday, and even with cooler temperatures, low elevation snow was still soft throughout on all aspects yesterday.

    • Avoid travel on or under steep slopes with saturated snow.
    • Roller balls, pin-wheels, and loose sluffs indicate potentially unstable wet snow.

  • Persistent Slabs

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

    Although increasingly unlikely, dangerous human triggered avalanches failing on a deeply buried persistent weak layer remain possible on isolated upper elevation slopes facing northwest, north, east, and southeast. Some avalanches might step down into buried persistent weak layers, involve large volumes of snow, and be quite dangerous and destructive.

Recent Activity

We have reports of a few easily triggered and manageable shallow drifts or soft wind slabs yesterday on upper and mid elevation slopes. Today's drifts will be stiffer and perhaps a bit less manageable. We triggered and noticed many other recent natural roller ball swarms and small loose sluffs in shady mid and lower elevation terrain in Card Canyon Sunday. This type of activity was widespread on steep slopes with saturated snow across the zone.

Sunday, 1-19-2020, a solo skier triggered and was caught and carried by a huge avalanche failing on a deep persistent weak layer in Miller Bowl near Tony Grove Lake. Luckily, the skier was able to walk away uninjured.

Paige approaching the large crown in Miller Bowl, 1-21-2020.

Snow and Weather

It's 25°F at the 8400' Tony Grove Snotel this morning, and there is about 11 inches of new snow from yesterday's storm, with 0.9" of Snow Water Equivalent. There is 79 inches of total snow, containing 124% of normal SWE. Winds are currently blowing from the west-northwest around 18 mph, and it's 18°F at the 9700' CSI Logan Peak weather station.

Several inches of fresh snow fell at upper elevations, and shallow powder conditions should be nice, especially in sheltered terrain. West-northwest winds dropped down into terrain in the Central Bear River Range yesterday and there was plenty of drifting going on. Low elevation temperatures have stayed above or around freezing for the last several days and the snow is quite soft and slushy. Expect mostly cloudy conditions in the mountains today, and an inch or two of snow in the afternoon. 8500' high temperatures are expected to be around 28°F, and 10 to 14 mph west-southwest winds. Snow will fall tonight, with 3 to 5 inches possible. Low temperatures will be around 16°F, with 10 to 14 mph west winds. Snow will continue in the mountains Wednesday, with 1 to 3 inches possible. It will be cloudy, with a high temperature near 23°F, and 10 mph west wind. High pressure aloft will expand across the Great Basin late in the week and remain through the weekend.

Additional Info

We noticed a few large fresh roof avalanches off metal barn roofs in the Bear Lake Area on Friday. Many are still holding lots of heavy snow, and gradual melting is causing them to drip and creep. Keep and eye on the kids, animals, and vehicles because more significant roof avalanche activity is likely in coming days.

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