Forecast for the Moab Area Mountains

Eric Trenbeath
Issued by Eric Trenbeath on
Friday morning, December 20, 2019
Blowing and drifting snow have created an isolated or MODERATE avalanche danger in steep upper elevation terrain. Look for fresh drifts, and older, harder wind slabs on the lee sides of ridge crests and terrain features such as sub-ridges or gully walls. Wind slabs may feel hollow underfoot, and cracking in the snow surface is a sign of instability. Most other terrain has LOW danger. We're also starting to see some developing layers of weak, sugary snow in the snowpack. Though not currently posing much of a problem, this is something we'll want to keep an eye on for the future.
Low
Moderate
Considerable
High
Extreme
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Special Announcements
The second UAC podcast of the season "Betting your life - why forecasting is poker not chess - a conversation with Jenna Malone" is now out.
The avalanche beacon tester is up and running at the Geyser Pass trailhead! Walk or ride past the sign on your way up - a red X means your beacon is off or not functioning, a green O means you're good to go! Thanks to UAC volunteer and supporter Kristi Jensen from Coyote Shuttle for helping me get it set up!
Road Conditions: The road is snow-packed and slick. All-wheel drive vehicles with good tires are recommended.
Grooming update: The main machine is back and ready for business! Matt will be up today marking trail and grooming.
Weather and Snow
24 Hour Snow 0" Weekly Snow 2" Base Depth in Gold Basin 28" Wind NW 10-20 mph Temp 12F
The story has been the wind and it's been blowing, drifting, and alternately scouring surfaces all week. It's been more than 2 weeks since our last significant snow and the surface is getting tired and worn. In my travels up and over Geyser Pass yesterday I still managed to find areas with soft settled powder below treeline, but the snowpack is deteriorating. Dry conditions will continue through the weekend before the first of possibly two troughs track into the region early next week. It's a little far out to say, but it's looking like Christmas could be white.
Ian Marynowski sent in this great observation from yesterday, in which he confirmed the continued presence of wind slabs in open, exposed terrain. He also noted some weak layers forming in the snowpack pretty much identical to what I found at the same elevation, but in a very different location. See more about this under Persistent Weak Layer.
And finally, Cody Marsh sent in this drone footage that illustrates snow conditions in the alpine. Seeing is believing, thanks Cody!
Wind, temperature, humidity on Pre Laurel Peak (11,700')
Storm totals at Gold Basin Study Plot (10,000').
Snotel site near Geyser Pass Trailhead (9600').
NWS weather forecast.
Recent Avalanches
I'm very sad to report that a 45-year-old man was killed in an avalanche while snowboarding in the backcountry outside of the Canyons Resort in the Wasatch Mountains on Sunday. Our deepest condolences go out to the family and friends who are so affected by this tragedy. Here is the final report.
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Avalanche Problem #1
Wind Drifted Snow
Type
Location
Likelihood
Size
Description
Winds over the course of the week have blown around what little snow was available for transport and isolated drifts have formed on the leeward sides of ridge crests and terrain features in upper elevation, wind exposed terrain. Fresh drifts are mostly shallow and shouldn't pose too much of a hazard, but they could sweep you off your feet and carry you over a cliff. Wind drifts are recognizable by their smooth, rounded appearance, and cracking in the snow is a sign of instability. The best practice is to avoid steep slopes with wind drifted snow.
Avalanche Problem #2
Persistent Weak Layer
Type
Location
Likelihood
Size
Description
The snowpack is showing signs of deterioration and it is becoming less cohesive, and slightly more loose and sugary. We are starting to see more faceting at the ground, and the mid-pack has a couple weak layers as well. This is definitely something we'll want to keep an eye on when more snow comes.
Snowpit profile from Ian Marynowski illustrates a similar snowpack.
General Announcements
The first UAC podcast of the season " Early Season Essentials with Program Director Bo Torrey" check it out HERE.
Get one of these cool t-shirts to support the UAC and other avalanche centers across the U.S.
This forecast is from the U.S. Forest Service, which is solely responsible for its content. This forecast describes general avalanche conditions and local variations always occur.