Forecast for the Logan Area Mountains
Issued by Toby Weed on
Tuesday morning, December 24, 2019
Tuesday morning, December 24, 2019
Heightened avalanche conditions and MODERATE danger exist on drifted upper and mid-elevation slopes in the backcountry. Today's fresh snow will hide yesterday's obvious hard drifts, but you could trigger an avalanche of wind drifted snow in exposed terrain. Dangerous avalanches failing on a dormant persistent weak layer near the ground are unlikely but remain possible on isolated upper elevation slopes facing northwest, north, northeast, and east.
Safer conditions and mostly LOW danger can be found in sheltered terrain and at lower elevations.
Safer conditions and mostly LOW danger can be found in sheltered terrain and at lower elevations.
- Evaluate snow and terrain carefully.
Low
Moderate
Considerable
High
Extreme
Learn how to read the forecast here
Weather and Snow
It's snowing and 28°F at the 8400' Tony Grove Snotel this morning, and there's 2 inches of new snow. I'm reading 44 inches of total snow, with 112% of average SWE for the date. It's 28°F on Logan Peak, and south winds continue to blow around 34 mph with a 60 mph gust earlier this morning.
A few inches of Holliday snow will go far to refresh conditions in the backcountry, and it won't be enough to increase the avalanche danger much. Heightened avalanche conditions exist on drifted upper and mid-elevation slopes. Strong and sustained southerly winds have been creating stiff drifts and wind slabs in exposed terrain, and a couple inches of new snow will hide yesterday's obvious wind deposits. Dangerous avalanches failing on a dormant persistent weak layer near the ground are unlikely for a person to trigger, but remain a possibility on isolated upper elevation slopes, especially on very steep rocky slopes with thin snow cover.
Snow showers are likely in the mountains today, with 1 to 3 inches possible. Expect 8500' high temperatures around 29°F, falling to around 23°F in the afternoon. 9 to 17 mph south-southwest winds will veer from the southeast in the afternoon. Snow showers should continue tonight, with another 1 to 3 inches possible. Low temperatures of around 20°F will be rising to around 27°F during the night, and expect 10 mph east-southeast winds. Snow showers are likely on Christmas Day, mainly in the morning, with less than an inch of accumulation expected. Temperatures will drop drop to around 18°F, and west winds will blow around 11 mph.
Recent Avalanches
No new avalanches were reported in the Logan Zone in the last week.
We checked out a large natural avalanche in the Central Wood Camp Bowls. (12-17-19)
Avalanche Problem #1
Wind Drifted Snow
Type
Location
Likelihood
Size
Description
Human triggered avalanches involving wind drifted snow are possible on upper and mid elevation slopes. The drifts and hard wind slabs formed by strong south winds in the last few days were buried and hidden from view by a couple inches of fresh snow overnight. Continuing south winds will easily drift the fresh snow onto steep slopes, and the soft, fresh drifts are likely to be quite sensitive today. Even small avalanches can be very dangerous in shallow snow conditions, because you could be dragged into rocks or stumps.
- Watch for and avoid stiffer drifted snow in and around terrain features like cliff bands, scoops, gully walls, and sub-ridges.
- While soft, fresh drifts may be quite sensitive, harder wind drifts might allow a person to get well out on them before releasing.
- Some wind slab avalanches might be triggered remotely or from a distance.
Avalanche Problem #2
Persistent Weak Layer
Type
Location
Likelihood
Size
Description
Weak sugary, faceted snow from late October still lurks near the ground at upper elevations on northwest through east facing slopes. Although gradually becoming unlikely for a person to trigger, large, destructive, and very dangerous avalanches are still possible where this poor snow structure exists. Deep slab avalanches might be triggered from a shallow area of the slab, so it's a good plan to avoid steep, thin, rocky terrain. Dangerous avalanches on isolated slopes still might be triggered remotely, from a distance, or below!
It looks like a few of the large natural avalanches from the weekend failed on a layer of smaller grained sugary or faceted snow that formed above the Thanksgiving storm snow.
This 12-14-19 natural avalanche near Tony Grove Lake failed on weak, sugary or faceted snow near the ground.
General Announcements
Remember the Beaver Mountain Backside is the backcountry. Buddy up! Everyone venturing beyond the ski area boundary should have a partner(s), beacon, probe, and shovel.
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.
Consider taking an avalanche class, there are many different options. Click on the Education menu for a full list of classes from the UAC and other providers. Check out the Know Before You Go eLearning program for free, online, avalanche classes.... HERE
Need a Christmas present for your favorite backcountry partner? Get one of these cool t-shirts to support the UAC and other avalanche centers across the U.S. HERE
It's key to head into the early avalanche season with the proper mindset. In this podcast, we talk with UAC program director Bo Torrey. Bo talks about particular risks unique to the early season, tips and tricks for knocking the rust off your early season rescue skills, and charts out the path forward with avalanche education. HERE
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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.
I will update this advisory before about 7:30 tomorrow morning.