Bollettino valanghe

Logan

Utah Avalanche Center
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Pericolo valanghe

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  • Limite del bosco
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In sintesi

Heightened avalanche conditions and MODERATE danger exist in the backcountry. Human triggered avalanches of fresh wind drifted snow are possible in exposed upper and mid elevation terrain. Also, on some upper elevation slopes, people could still trigger dangerous avalanches failing on a deeply buried persistent weak layer.

  • Evaluate snow and terrain carefully.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2

    Yesterday, winds from the west-northwest moved the fresh snow around and created soft and stiffer drifts on upper and mid elevation slopes that may still be sensitive to human triggering today.

    • 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.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    3

    Human triggered avalanches failing on a buried persistent weak layer are possible on upper elevation slopes. Apparently, some avalanches can step down into buried persistent weak layers, involve large volumes of snow, and be quite dangerous and destructive. The cold weather Christmas week created sugary weak surface snow in many areas, in others a layer of surface hoar feathers was buried by the New Years Storm. Recent activity in the zone shows that additional weight from tons of recent snow and significant drifting last week was enough to reactivate the deeply buried October persistent weak layer on some slopes. You can still find this weak sugary basal layer lurking on upper elevation slopes facing northwest, north and east.

    • Some avalanches might still be triggered remotely, from a distance, or below.
    • Smaller avalanches overrunning a slope with buried persistent weak layers could step down into old snow and initiate a much larger avalanche.

    Sugary, faceted snow from a buried weak layer that failed in Sunday's Miller Bowl Avalanche on a north facing slope at about 8700' (1-21-2020)

Snow and Weather

It's 26°F at the 8400' Tony Grove Snotel this morning, and there is 6 inches of new snow from yesterday, with 0.8" Snow Water Equivalent. There's 80 inches of total snow, containing 126% of normal SWE. West and northwest winds have been fairly consistent overnight at the CSI Logan Peak weather station. They are currently blowing from the northwest around 20 mph, and it's 20°F at 9700'.

A few inches of fresh snow helped to refresh riding conditions in the backcountry, but northwest winds moved snow around at upper elevations. Today, soft and stiffer drifts of fresh snow are likely to still be sensitive to human triggering in exposed upper elevation terrain.

Snow is likely in the mountains today, with 1 to 3 inches of accumulation possible. 8500' high temperatures will be around 30°F, with 11 to 14 mph west winds. It will be mostly cloudy tonight, with temperatures rising to near 25°F. West wind will blow 8 to 10 mph. A fast-moving trough will impact the Logan Zone Friday, with 1 to 3 inches possible. High temperatures will be around 31°F, with 6 to 13 mph southwest wind. High pressure aloft will return for the weekend.

Additional Info

Here is a short video about Saturday's tragic fatal accident in Farmington Canyon.

Special Announcement

We are very sad to report an avalanche fatality that happened Saturday above Farmington Canyon. A 18 year old, male snowmobiler was caught, fully buried and killed. The final report is available HERE. Our deepest condolences go out to the friends, family, rescuers, and everyone affected by this tragic accident.

Recent Activity

Sunday, a solo skier triggered and was caught and carried by a huge avalanche in Miller Bowl near Tony Grove Lake. Luckily, the skier was spit out the flank at the bottom, just as the very deep pile of debris came to a stop. The avalanche on a repeater path at about 8700' was 4 to 5 feet deep and about 350 feet wide. It failed on a deeply buried sugary persistent weak layer near the ground with a loud thunderous roar, and took the skier under the snow for a harrowing spin-cycle ride. The very lucky skier lost both skis and ski poles, but is happy and grateful to have walked out alive.

A large natural or perhaps remote triggered avalanche was observed in the Fairgrounds on the east side of Logan Peak Sunday, 1-19-2020. There were no visible tracks in the area when it was first spotted.

General Announcements

New UAC Podcast - An Avalanche Forecaster, a Meteorologist, and an Economist Walk Into a Bar..... 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.

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