Avalanche forecast

Logan

Utah Avalanche Center
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Avalanche danger

  • Alpine
  • Treeline
  • Below treeline
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Highlights

Merry Christmas Eve!

Today the avalanche danger is CONSIDERABLE on all mid and upper elevation terrain as well as all low elevation terrain facing E, N, & W. Wednesday's winds and snowfall created widespread slabs of wind drifted snow that may be a problem on their own, but they have overloaded a buried persistent weak layer buried 2-4 feet deep.

The danger is MODERATE on low elevation, southerly facing slopes.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2

    There's a good chance a person can trigger a slab avalanche on a buried persistent weak layer of facets 2-4 feet deep (photo below). Where the snow is deepest, this layer may be starting to gain some strength as two regular observers found on Thursday, but they experienced one very loud collapse which then told them the opposite. In areas with shallower snow, like low elevations or places scoured by winds, this layer remains weak.

    My partner and I rode throughout Copenhagen Basin yesterday and found an unstable layer of surface hoar on top of these facets (video below), and we would have easily triggered a slide if we had gotten on a steep slope. Toby checked out low elevation avalanche activity in Garden City where the snowpack was thin and weak, and then overloaded by wind drifting.

    I would avoid avalanche terrain simply because this layer exists. With the potential for a lot of snow next week, things could change a lot (probably for the better) in coming weeks.

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    3

    Hard slabs of wind drifted snow may produce avalanches on their own, but the likelihood should be quickly decreasing. The main danger with these hard wind slabs from Wednesday's winds is triggering a deeper avalanche that fracures on the persistent weak layer discussed above. What makes these hard slabs so tricky is that they can be a little more stubborn, and they can let a person get further onto them before they avalanche. Or they may let several people ride on top of them before sliding.

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Recent Activity

Avalanche activity spiked following Wednesday's snow and wind. These slides were spotted at all elevations like ones near Garden City by Bear Lake, in Logan Canyon, and at upper elevations like one seen near 9000 feet in the Mt Naomi Wilderness that was estimated to be 2-3 feet deep and 400 feet wide (photo below).

No slides were reported yesterday; however, my partner and I experienced plenty of collapsing further north in Copenhagen Basin near Hwy 36. Collapsing is the same as triggering an avalanche except we were on low angle slopes not steep enough to slide.

***See our updated list of observed avalanches from the Logan Zone HERE and from across Utah HERE

Snow and Weather

It's snowing this morning with just an inch or so of new snow accumulating since yesterday. Temperatures range from the low to upper 20s F. Winds are blowing from the WNW 7-18 mph with gusts in the low 20s.

Winds from the northwest will bring a few disturbances (aka very small storms) over the area today and tomorrow. Snow will continue falling this morning before drying out this afternoon with maybe just another inch of snow accumulating. A little more snow may fall tonight or tomorrow but only a trace to an inch. Temperatures today will only rise a few degrees, and winds at ridgetops will blow 10-15 mph.

Looking ahead - A short-lived ridge (dry weather) will be over the area Monday and part of Tuesday. Sometime Tuesday a prolonged period of precipitation should begin. Warm air should arrive with this precip on Tuesday which means the valleys should get some rain but the mountains will get snow, probably a lot.

Wednesday's strong winds drifted a lot of snow and created many hard slabs, but really nice dense powder can still be found in sheltered terrain. However, those strong winds have also created dangerous avalanche conditions.

Additional Info

Take the all-new online avalanche courses the UAC built for Know Before You Go or take other online courses listed on the KBYG website (Develop skills -> Online Learning).

Remember, when you leave the ski area boundary, Beaver Mt or Cherry Peak, you are entering the backcountry, and you could trigger dangerous avalanches....

  • Put fresh batteries in your transceiver and inspect your shovel and probe.
  • Practice Companion Rescue with your backcountry partners.

General Announcements

Please submit your observations from the backcountry HERE.

For a list of avalanche classes from the Utah Avalanche Center go HERE

For information on where you can ride your sled or snowbike, check out this map of the winter travel plan for the Tony Grove and Franklin Basin Areas HERE.

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.

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