Forecast for the Logan Area Mountains
Issued by Toby Weed on
Saturday morning, December 21, 2019
Saturday morning, December 21, 2019
Heightened avalanche conditions and MODERATE danger exist on upper elevation slopes in the backcountry. You could trigger an avalanche of wind drifted snow in exposed terrain. Dangerous deep slab avalanches failing on a persistent weak layer are becoming unlikely for a person to trigger, but they remain possible on some upper elevation slopes facing northwest, north, northeast, and east. You can find very nice and fast recrystallized powder, much safer conditions, decent coverage, and LOW danger on most other slopes.
- Evaluate snow and terrain carefully.
Low
Moderate
Considerable
High
Extreme
Learn how to read the forecast here
Weather and Snow
It's 30°F at the 8400' Tony Grove Snotel this morning, and I'm reading 46 inches of total snow, with 112% of average SWE for the date. It's 29°F on Logan Peak, and south winds picked up a bit overnight and are blowing around 30 mph.
Snow in exposed terrain was already getting wind-jacked up in Bloomington Canyon yesterday. Stiff drifts may have formed on weak and sugary surface snow in some areas.
A strong high pressure system will remain entrenched over the zone through the weekend, but increasing winds aloft will try to mix it out. Expect mostly sunny conditions in the mountains today, with 8500' high temperatures around 36°F and south-southwest winds 13 to 18 mph. It will be mostly cloudy tonight with low temperatures around 18°F and south-southwest winds 18 to 21 mph. It will be mostly cloudy on Sunday, with high temperatures around 37°F, and it will be rather breezy, with south-southwest wind around 23 mph.
Recrystallized powder conditions are fantastic, even in sunny and lower elevation terrain, but increasing south-southwest winds this weekend will create more variable surface conditions. Heightened avalanche conditions exist on some drifted upper elevation slopes, and continuing and increasing south-southwest winds over the weekend will probably make the problem more widespread. Dangerous and destructive avalanches failing on a deep persistent weak layer are gradually becoming more unlikely, but remain possible on some shady upper elevation slopes.
Recent Avalanches
I'm sorry to report Utah's first avalanche fatality this season. On Sunday 12-15-19, a 45 year old male snowboarder was killed in a backcountry avalanche in Dutch Draw in the Wasatch Mountains above Park City.
Here is the Accident Report
Locally:
No new avalanches were reported in the Logan Zone since last weekend's natural cycle that occurred during the windy storm. We observed evidence of several large natural avalanches on Sunday. These were generally 3' to 4' deep and a few hundred feet wide, including Miller Bowl, East (above Tony Grove Lake) which took down some trees and ran to the flats. Recent large natural avalanches were also observed in Wood Camp, and on Providence Peak, Naomi Peak, and Cornice Ridge.
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 elevation slopes.
- Watch for and avoid stiffer drifted snow in and around terrain features like cliff bands, scoops, gully walls, and sub-ridges.
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Even small avalanches can be very dangerous in shallow snow conditions, because you could be dragged into rocks or stumps.
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 some shady northerly 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. Dangerous avalanches on some 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 week's high pressure is causing the nice surface snow to rapidly become weak and sugary or faceted on slopes at all elevations, and pretty feathers of surface hoar adorn the surface in many areas. This weekend's wind and warmth hopefully will destroy the weak surface snow on many slopes before it is buried next week.
This 12-14-19 natural avalanche near Tony Grove Lake failed on weak, sugary or faceted snow near the ground.
Additional Information
I will update this advisory before about 7:30 Monday morning.
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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