Forecast for the Logan Area Mountains
Issued by Toby Weed on
Sunday morning, December 8, 2019
Sunday morning, December 8, 2019
Snow and wind with today's storm will cause rising avalanche danger. Heightened avalanche conditions already exist this morning, and areas with CONSIDERABLE danger will likely develop on drifted slopes and in steep shady terrain at upper elevations. Human triggered avalanches of wind drifted snow will become increasingly likely, and you could still trigger a dangerous avalanche failing on a persistent weak layer of loose sugary snow near the ground. Safer conditions can be found at lower elevations, in sheltered terrain, and on sunny slopes that were bare before the Thanksgiving storm.
- Avoid steep wind drifted slopes.
- Evaluate snow and terrain carefully.Use caution while route finding, and make conservative decisions.
Low
Moderate
Considerable
High
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Weather and Snow
It's 33°F at the 8400' Tony Grove Snotel this morning, and it's snowing, with an inch of new snow at 4:00 AM. I'm reading 29 inches of total snow containing 7.1" SWE, which is 95% of normal for the date. It's 26°F at the 9700' CSI Logan Peak weather station, and southwest winds are blowing about 30 mph, with a 50 mph gust earlier this morning. Drifting snow from sustained southerly wind created elevated potential for human triggered avalanches, and pockets with dangerous avalanche conditions persist on upper elevation slopes facing east, northeast, north, and northwest, where a person is likely to trigger a dangerous avalanche failing on a buried persistent weak layer near the ground.
Expect snow and increasing avalanche danger in the mountains today, with 4 to 8 inches of accumulation possible and 20 to 25 mph west winds. 8500' high temperatures are around 33°F this morning, but they will drop to around 25°F this evening. Snow showers will continue in the mountains tonight, with 2 to 4 additional inches possible. Temperatures will be around 17°F, and 16 to 21 mph west winds are expected. Snow showers will continue tomorrow morning, with high temperatures around 26°F, with 15 to 22 mph northwest winds. The next round of winter weather is expected around midweek, with potential for a decent storm next weekend.
Recent Avalanches
Two riders were caught and carried, and one of them was partially buried in an avalanche just north of the Idaho State Line on Saturday afternoon. Here's the report.
Tuesday, a solo skier unintentionally triggered a good sized avalanche failing on the sugary persistent weak layer near the ground in the west half of Miller Bowl south of Tony Grove Lake. The avalanche on a north facing slope at around 8700' was around 2' deep and at least 150' wide.
Avalanche Problem #1
Persistent Weak Layer
Type
Location
Likelihood
Size
Description
Most sunny slopes were bare and many others patchy or crusty after the prolonged November dry spell. But on slopes above about 8000' facing northwest, north, and northeast, the old October snow has grown sugary and very weak. Dangerous and destructive avalanches failing near the ground are possible, and the danger on many of these slopes will persist for a while. The snow is gradually becoming more stable, but avalanches on some slopes could still be triggered remotely, from a distance, or below! Tuesday's close call in Miller Bowl near Tony Grove Lake confirms that dangerous human triggered avalanches remain possible in some areas.
- Cracking and collapsing are red flags indicating unstable snow conditions.
Avalanche Problem #2
Wind Drifted Snow
Type
Location
Likelihood
Size
Description
South winds sustained average speeds in the 30's with gusts in the 50s on Logan Peak yesterday and overnight. I'm seeing a westerly shift in the wind this morning on Logan Peak. Today's fresh snow will easily be picked up and drifted into lee slope deposition areas. Stiff older and soft fresh drifts are both likely to be sensitive to human triggering, so as usual, avoid steep slopes with recently drifted snow.
- Even small avalanches can be very dangerous in shallow snow conditions, because you could be dragged into rocks or stumps.
Additional Information
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.
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
General Announcements
The Tony Grove Road is not maintained for wheeled vehicles in the winter, and it is snowpacked, narrow, and icy in places. You could easily get stuck in deep snow, and it doesn't look like anyone was able to drive very far up recently. Hikers, cross country skiers, snow bikers, dogs, sleds, and 4x4s share the road this time of year, so be nice and keep your speed down around others.
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