Bollettino valanghe

Logan

Utah Avalanche Center
Vedi sulla mappa

Pericolo valanghe

  • Alta quota
  • Limite del bosco
  • Sotto il limite del bosco
Open full map
Non aggiornato — questo bollettino è scaduto 4 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Heavy snow and drifting overloaded slopes with widespread buried persistent weak layers and created dangerous avalanche conditions in the backcountry. CONSIDERABLE danger exists on all upper and mid elevation slopes, with dangerous human triggered avalanches likely and natural avalanches possible. Avalanches could be triggered from a good distance away or even from the flats below steep slopes. Cooler temperatures are helping to set up the remaining saturated snow at lower elevations but elevated conditions still exist, especially where there is still a couple feet of snow on the ground.

  • We plan to continue to stay off and out from under backcountry slopes steeper than 30 degrees.
  • Careful snowpack evaluation, cautious route finding, and conservative decision making are essential for safe backcountry travel.

Problemi valanghivi

  • Persistent Slabs

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

    Persistent weak layers formed in November continue to plague many slopes, and last week's windy storm created a thick slab overlaying the weak layers, which created poor snow structure and an unstable snow situation in many areas.

    There's a good chance a person can trigger a slab avalanche on a buried persistent weak layer of facets 1-4 feet deep. Where the snow is deepest like at upper elevations, this layer may be starting to gain some strength, meaning it'll hold a thicker , heavier slab before failing. But in areas with shallower snow, like low elevations or places scoured by winds, this widespread layer of loose sugary snow remains weak.

    Mark rode throughout Copenhagen Basin Friday and found an unstable layer of surface hoar on top of these facets. He thought he would have easily triggered a slide if he had tried to ride on a steep slope. The party experienced plenty of collapsing.

    I was in the area on Wednesday and did not trigger any collapsing but found the November persistent weak layer as well. (see video below)

  • Storm Slabs

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

    Soft slab and loose avalanches of new snow are likely on their own in steep terrain. Underlying persistent weak layers and poor snow structure aside, soft slabs of heavier storm snow could fail within the storm snow itself or on the old snow interface.

    Be especially wary in recently drifted terrain, on the lee side of major ridges, corniced slopes, in and around terrain features like gullies, sub-ridges, cliff bands, and sinks.

Recent Activity

  • No new avalanches were reported yesterday, but one backcountry skier reported a huge whumpf on a mid elevation west facing slope.
  • Rain melted significant lower elevation snow and spawned several natural wet avalanches running into the Logan River and off other steep lower elevation slopes across the zone on Tuesday.
  • A large avalanche was reported near Logan Peak, occurring around 12/23. It was large and destructive, and it likely failed on facets.
  • ***See our updated list of observed avalanches from the Logan Zone HERE and from across Utah HERE

Special Announcement

As the end of the year approaches, please consider a donation to the UAC to support avalanche forecasting.

Didn’t get what you want for Christmas? Do your loved ones simply give you money for the holidays and say “Go buy something for yourself?” Support the UAC and get a great gift for yourself or your loved one at our Holiday Auction. The auction closes at 8:00 PM MT on January 2, 2023.

Snow and Weather

Lots of very heavy snow fell across the Logan Zone Tuesday night, falling on widespread slopes with poor snow structure, slabs of previously wind drifted snow overlaying buried persistent weak layers buried 2 to 4 feet deep. Avalanches could be triggered remotely, from a distance or below. Large and long running natural avalanches will become likely again tomorrow as heavy snow and drifting will continue to build thick unstable slabs.

The Good News:

  • The storm train is dumping a ton of very heavy wet snow, which is very good for our overall water situation.
  • Temperatures dropped significantly at lower elevations, which stopped the meltdown and is freezing up the rain soaked snow.
  • Powder riding conditions are really fast and good in low angled terrain, and we've been able to find great safe conditions while staying off and out from under steeper slopes.

  • I'm reading a cool 13° F at the 8400' Tony Grove Snotel, and there is 18 inches of new snow from the first storm, with 2.4" of SWE. There is now 62 inches of total snow. Overnight the winds at the 9700' CSI Logan Peak weather station diminished a bit, now blowing from the west-northwest at 18 mph with gusts to around 30 mph.
  • Today, we'll see a break in snowfall, but it'll be mostly cloudy and temperatures hovering below around 20° F. Winds generally blowing from the west-southwest at 15 to 20 mph are expected.
  • Looks like the next significant winter storm is on tap, beginning tomorrow and lasting into next year. Significant snow accumulation is expected in the mountains, likely measured in feet rather than inches.

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

As the end of the year approaches, please consider a donation to the UAC to support avalanche forecasting.

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.

Regioni coperte