Forecast for the Logan Area Mountains
Issued by Toby Weed on
Thursday morning, December 5, 2019
Thursday morning, December 5, 2019
Heightened avalanche conditions exist in steep shady terrain at upper elevations, and you could trigger a 2' to 3' deep avalanche failing on a persistent weak layer of loose sugary snow near the ground. The snow is gradually becoming more stable, but avalanches on some slopes could still be triggered remotely, from a distance, or below! You can find much safer conditions and LOW danger at lower elevations, in sheltered terrain, and on slopes that were bare before the Thanksgiving storm.
- Evaluate snow and terrain carefully.
Low
Moderate
Considerable
High
Extreme
Learn how to read the forecast here
Special Announcements
This evening we are offering a free Avalanche Tune Up Talk at Northstars in Preston ID at 6:00.
Weather and Snow
There's a couple inches of new snow and it's 26°F at the 8400' Tony Grove Snotel this morning. I'm reading 31 inches of total snow containing 6.9" SWE, which is 104% of normal for the date. It's 24°F at the 9700' CSI Logan Peak weather station, and south-southwest winds are blowing about 16 mph. Heightened avalanche conditions persist on drifted upper elevation slopes facing northeast, north, and northwest, and dangerous human triggered avalanches up to about 3-feet-deep remain possible.
Snow showers will continue this morning, but not much accumulation is expected. Temperatures will gradually drop during the day and bottom out around 25°F and winds will be fairly calm. It'll be cloudy in the mountains tonight, with temperatures around 27°F and calm winds becoming light from the northeast. It will be cloudy on Friday, with high temperatures around 34°F, and 3-5 mph southwest wind. A progressive but weakening storm will bring several inches of snow to the Logan Zone later in the weekend.
Recent Avalanches
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.
A natural avalanche involving wind drifted snow was spotted by observers Sunday (12-1-19) on the west side of Logan Peak in upper Logan Dry Canyon. The fresh avalanche was about 1 foot deep and 300 feet 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. Tuesday's close call in Miller Bowl near Tony Grove Lake confirms that dangerous human triggered avalanches remain possible in some areas.
- Even small avalanches can be very dangerous in shallow snow conditions, because you could be dragged into rocks or stumps.
- Cracking and collapsing are red flags indicating unstable snow conditions.
Additional Information
Welcome to the First Annual Avalanche Awareness Week. We have 20 events scheduled for this week. Check out the schedule here and we hope to see you at an event. HERE
Almost 100 people showed up at the USU Outdoor Program HQ for our Know Before You Go talk Tuesday night.
- 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