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

Points saillants

Dangerous avalanche conditions exist and there is CONSIDERABLE danger on upper and mid elevation slopes. People are likely to trigger loose avalanches of new snow on steep slopes, soft slab avalanches where fresh snow has been drifted, and possibly dangerous harder slab avalanches failing on a sugary buried persistent weak layer near the ground. You'll find safer conditions in sheltered lower angled and lower elevation terrain.

  • Evaluate snow carefully, use caution route-finding, and make conservative decisions.
  • Stay off and out from under drifted slopes steeper than about 30 degrees.

Problèmes avalancheux

  • Wind Slabs

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

    Today's moderate south west winds are enough to drift fresh snow into lee slope avalanche starting zones and build drifts high on steep slopes. Soft wind slab avalanches triggered by people are likely today on steep mid and upper elevation slopes facing northwest through southeast.

    • Watch for and avoid drifted snow at upper and mid elevations near ridge tops and in and around terrain features like gullies, scoops, cliff bands, and sub ridges.

    We cracked out this shallow but hard wind slab near the saddle on Beaver Mountain Backside Thursday. There are more old hard drifts and lots of soft new ones out there that could be triggered.

  • Persistent Slabs

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

    Very weak sugary or faceted snow near the ground is widespread across the region, and people could trigger avalanches where a slab of more cohesive snow has formed on top of the weak snow.

    • Avalanches failing on a buried persistent weak layer might be triggered remotely, from a distance, or worse from below!
    • Cracking and collapsing of the snow are a red flag, indicating unstable snow conditions.

    Still finding propagation in snow pit tests Thursday on an east-northeast facing slope at 8400' in the backcountry on the backside of Beaver Mountain. This layer could easily be reactivated by the new load from today's storm.

  • Storm Slabs

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

    Sluffs or loose dry avalanches of new snow are likely in steep terrain, and these could be fast and run pretty far on weak snow that was on the snow surface before the recent storm. In some areas, moderate south and west winds may have created more cohesive slabs of new snow, and soft slab avalanches are possible for people to trigger. A small avalanche overrunning a slope with poor snow structure could cause a larger, more dangerous avalanche. The load of the new snow may be enough in some areas to overload deeper buried persistent weak layers that are widespread across the zone, and large natural and human triggered avalanches could result.

Recent Activity

Observers yesterday reported triggering loose dry avalanches or sluffs of new snow in the Central Bear River Range, which were fairly fast and long running.

There were several larger skier triggered slab avalanches in the Cutler Ridge Area in the Ogden backcountry where more snow fell yesterday, but nobody got caught.

Lots of snow fell in the Ben Lomond Area and in the north fork of the Ogden Valley, and there were a few pretty big avalanches triggered by people.

  • A local rider was completely buried in Steep Hollow on 1-8-2021. Thankfully, he was rescued in time by his riding partners. Our accident report shows the details.. HERE
  • In early January there were several large remotely triggered avalanches in the Logan Zone, all triggered by sledders or snow bikers, and luckily from a distance. See the avalanche list HERE.

Snow and Weather

It's snowing lightly this morning, and 4 or 5 inches of new snow fell yesterday at upper elevations in the Bear River Range. It looks like a bit more fell in the southern part of the zone and in the Wellsville Range. The 8400' TGLU1 Snotel reports only 63% of normal SWE for the date, and the existing snowpack is generally quite shallow in the Logan Zone. We have a serious problem with widespread very weak sugary snow and a dangerous persistent weak layer near the ground on many slopes.

Today will be partly sunny, with 8500' high temperatures around 22°F, a moderate westerly breeze, wind wind chill values as low as -4°F. More snow is likely this week in a progressive weather pattern, but the bulk of the moisture and energy of the next storm will pass mostly to our south.

Additional Info

Do you have the essential avalanche rescue gear (transceiver, probe, and shovel) and do you know how to use them? Watch this video to see how the three pieces of equipment work together. HERE

This video is from the 1-8-2021 avalanche in Steep Hollow that completely buried a local snow bike rider.

Please use the Beacon Training Park and Beacon Checker at the Franklin Basin Trailhead...

General Announcements

Thanks to the generous support of our local resorts, Ski Utah, and Backcountry, discount lift tickets are now available. Support the UAC while you ski at the resorts this season. Tickets are available here.

Visit this website with information about Responsible Winter Recreation by the Utah Office of Outdoor Recreation.

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 clickingHERE, or include #utavy in your tweet or Instagram.

I will update this forecast by around 7:30 tomorrow morning.

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.

Régions couvertes