Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Monday - January 18, 2016 - 7:25am
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CONSIDERABLE (level 3): Dangerous avalanche conditions exist and careful snowpack evaluation, cautious routefinding and conservative decision-making will be essential in the backcountry today. Triggered avalanches are likely on recently drifted slopes steeper than about 30 degrees, and natural wind slab and/or wet avalanches are possible in some areas. ​​ Continue to avoid travel on or beneath steep drifted slopes. Avalanches could be triggered remotely, from a distance or even below!




current conditions

Dangerous avalanche conditions still exist today on drifted slopes in the backcountry, and you should continue to stay off of and out from under drifted slopes steeper than about 30 degrees. The temperature is a balmy 27 degrees and I'm reading one inch of new snow from overnight at the 8400' Tony Grove Snotel. There's now 61 inches of total snow, containing 95% of average water content for the date. The 9700' CSI Logan Peak weather station reports 22 degrees this morning and significantly increased southwest winds overnight, with current wind speeds averaging around 26 mph, and gusting into the mid forties.


I triggered several fairly deep shooting cracks yesterday in drifted lower angle terrain. These are a sure sign of instability. (1-17-2015)
recent activity

I don't know the story, but it occurred yesterday afternoon. Looks like skier (or rider) triggered as I could see both types of tracks entering this small avalanche just above the backside parking. Remember, the backside of Beaver Mt. is the backcountry. You need to carry and practice with a beacon, probe, and shovel, and practice good backcountry travel protocols by only exposing one person at a time to a steep slope and going with a group or at least a partner. (1-17-2015)

  • At least one unintentional triggered avalanche occurred yesterday in backcountry terrain accessed from Beaver Mt.
  • Observers report seeing some natural avalanches on the western slope of the Bear River Range from Cache Valley, and I could see a few from the Top of Beaver Mt. yesterday. But, we saw less natural avalanches than I thought we would.
  • Observers in the Ogden and Salt Lake Area mountains reported triggered avalanche activity from the backcountry Saturday, and a backcountry skier was caught, carried, partially buried, and lost both skis in an avalanche in the Wasatch Range.
  • Local observers report easily triggering numerous sensitive fresh wind slabs, some remotely, in the Tony Grove Area Friday.
  • Natural wind slab activity occurred in many areas last week at upper elevations due to drifting, and we were easily able to trigger a foot-deep hard wind slab on an upper elevation test slope Wednesday.
  • A rider triggered, was caught, carried, partially buried, and injurred on New Years Eve in a large and scary avalanche on a slope with a history of avalanche accidents in the Middle Fork of St. Charles Canyon a few miles north of the Idaho State Line. Video Report

***To view our updated list of backcountry observations and avalanche activity from around Utah, go to our observations page

Avalanche Problem 1
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 24 hours
description

Southwest winds intensified overnight, and drifting snow from westerly winds Saturday night built fresh drifts in deposition areas and added weight to existing wind slabs. Many of these were sensitive to human triggering yesterday, and more drifting is likely during accumulating snowfall today. Avoid recent drifts and/or stiffer wind slabs near ridge tops and in and around terrain features like gullies, sub-ridges, scoops, and rock outcroppings. Many wind slabs probably formed on weak faceted or feathery snow that was previously on the snow surface, which means the slabs could be reactive to our weight, and the older drifts may stay sensitive to human triggering for several days.
Avalanche Problem 2
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 24 hours
description

Earlier in the week, we found widespread loose and very weak snow on the surface, and now a slab layer consisting of drifted new snow has accumulated on it. Triggered persistent slab avalanches are likely in some areas today, and last week's weak surface snow is now a buried persistent weak layer that could stay reactive for several days at least. Avalanches are possible on steep slopes with significant fresh and drifted accumulations even in sheltered terrain and at lower elevations. In some areas, the faceted snow in the basal layers of the snowpack may become reactivated by the recently added weight of drifted new snow. Dangerous and destructive avalanches involving old snow and failing on sugary faceted snow or depth hoar are possible today, especially in areas with shallow snow cover and poor snow structure.

***Pay close attention to signs of unstable snow like recent avalanches, whumpfing, and shooting cracks, and be willing to reevaluate your plans. In these conditions you could trigger avalanches remotely, from a distance or worse, from below!
Avalanche Problem 3
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 24 hours
description

We noticed lots of rollers and a few loose wet avalanches at lower elevations in Logan Canyon yesterday. It's raining down low this morning, and I'm unsure how high (or low) the rain/snow line is. Wet avalanches are certainly possible today on steep lower elevation slopes with saturated fresh snow and more rain or a higher rain/snow line could cause dangerous conditions with significant natural activity possible. Today is not a good day for fishing in the Logan River or recreating at lower elevations below steep snow covered slopes....

weather

Expect snow in the mountains today, with a 8500' high temperature around 31 degrees and southwest wind in the 15 to 20 mph range. 3 to 7 inches of accumulation is expected. Snow is likely tonight before around 2300 hrs, with 1 or 2 more inches possible, temperatures will drop to around 18 degrees and west winds are expected to diminish a bit. It'll be mostly cloudy tomorrow with a high near 29 degrees and moderate southwest wind. The next wave of storminess will arrive Tuesday night, with west winds and 5 to 9 inches of accumulation possible.
general announcements

Presenting our Avalanche Awareness Class in Logan beginning the January 21, with a full field day in the backcountry on Saturday January 23.   Go HERE for more information and to sign up.

The CROWBAR backcountry ski race will be Saturday January 30. More info at http://CrowbarSkiRace.org.

Please submit snow and avalanche observations from your ventures in the backcountry HERE. You can call us at 801-524-5304 or email HERE, or include #utavy in your Instagram or Tweet us @UAClogan. To report avalanche activity in the Logan Area or to contact the local avalanche forecaster call me, Toby, at 435-757-7578. 

I'll update this advisory throughout the season on Monday, Wednesday, Friday, and Saturday mornings by about 7:30

This advisory is produced by the U.S.D.A. Forest Service, which is solely responsible for its content. It describes only general avalanche conditions and local variations always exist.