Forecast for the Logan Area Mountains
Issued by Toby Weed on
Friday morning, January 24, 2020
Friday morning, January 24, 2020
Human triggered avalanches of wind drifted snow are possible and the danger MODERATE in exposed upper elevation terrain. On some isolated upper elevation slopes, people might still be able to trigger dangerous avalanches failing on a deeply buried persistent weak layer. Also, rain falling on the snow at lower elevations today could cause some potential for wet avalanches.
- Evaluate snow and terrain carefully.
Low
Moderate
Considerable
High
Extreme
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Special Announcements
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.
Weather and Snow
It's 27°F at the 8400' Tony Grove Snotel this morning, and there is 78 inches of total snow, containing 124% of normal SWE. Winds are currently blowing from the southwest around 20 mph, and it's 22°F at the 9700' CSI Logan Peak weather station.
A few inches of fresh snow helped to refresh riding conditions in the backcountry, but northwest winds moved snow around at upper elevations. Observers near the state line and the northern part of the zone report a thin rime crust at upper elevations on all aspects. Today, stiffer drifts of Wednesday's snow in exposed upper elevation terrain are likely to be rather stubborn, and some may allow a person to get out on them before releasing.
Rime needles grow into the wind. This at 8500' in Garden City Bowls.
Snow is likely in the mountains today, with 2 to 4 inches of accumulation possible. Some rain or a rain-snow mix may fall on the snow at lower elevations. 8500' high temperatures will be around 30°F, with 7 to 9 mph southwest winds. Snow showers will continue tonight, with 1 to 3 inches possible, low temperatures around 21°F, and west winds will blow around 9 mph. High pressure aloft will return for most of the weekend. Saturday will be mostly cloudy, with a high temperature near 28°F and 7 to 10 mph west-southwest wind. The next storm system will approach the region late Sunday.
Recent Avalanches
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.
Avalanche Problem #1
Wind Drifted Snow
Type
Location
Likelihood
Size
Description
Wednesday, winds from the west-northwest moved the fresh snow around and created soft and stiffer drifts on upper elevation slopes, and some may still be sensitive to human triggering today. Light winds today shouldn't cause much drifting, even as some snow is falling, but watch out for older drifts which will now be hiding under today's fresh coating of new snow.
- 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.
Avalanche Problem #2
Persistent Weak Layer
Type
Location
Likelihood
Size
Description
Human triggered avalanches failing on a buried persistent weak layer are possible on isolated 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. Recent activity in the zone shows that the weight from last week's snow and drifting 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.
The cold weather Christmas week created sugary weak surface snow in many areas, and we've been finding areas with poor snowpack structure where the snow was shallow in the early season. We're paying close attention to lower and mid elevation slopes, and our tests are now showing propagation on the sugary mid-pack weak layer in some places.
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)
Avalanche Problem #3
Wet Snow
Type
Location
Likelihood
Size
Description
A bit of rain may fall on lower elevation slopes today. If so, wet avalanches will be possible on steep slopes with soft saturated snow.
Additional Information
Here is a short video about Saturday's tragic fatal accident in Farmington Canyon.
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.