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Logan area Avalanche statement

Wednesday December 12, 2007

Hello and good morning, this is Toby Weed of the Utah Avalanche Center with your Logan Area backcountry avalanche and mountain weather advisory.  It’s Wednesday December 12th and it’s about 7:30 in the morning.  This advisory is brought to you in part by the Friends of the Utah Avalanche Center in Logan with help from Backcountry.com.

             Current Conditions:

Frigid temperatures in the mountains are keeping the powder conditions good, but we’re still horribly limited by lack of snow.  I managed to do more substantial damage to my ski bases twice yesterday when I squarely hit completely invisible but only shallowly buried rocks.  The best turning conditions can be found on the mostly tracked-out north facing grassy slopes south of Tony Grove Lake, while riding is limited to roads and upper elevation meadows  It’s a bone-chilling 6 degrees this morning at the CSI weather station at 9400’ on Logan Peak, and the wind is from the northwest at around 20 mph. There’s only 22 inches of total snow on the ground at the Tony Grove Snotel containing a piddley 3 inches of water; only 34% of average for the date.

 It’s a good idea in the early season to practice with all your rescue equipment.  I recommend putting a transmitting beacon in your pack and burying it for you partners to find using their probes.  Now is a good time to work out any bugs in your party’s rescue preparedness.  

            Avalanche Conditions:

Ski-cuts in the backcountry and explosive control work at ski areas in the Central Wasatch continue to produce scary full depth avalanches on north facing slopes. My party triggered numerous audible collapses or woomphing noises yesterday in untracked low–angled terrain between 8500’ and 9500’ in the Central Bear River Range.  The collapses ranged from subtle “quite” drops in the snowpack that sounded like a distant drum beat, to much more extensive booms, in which an acre or more of snowpack in a meadow would drop and we could see bushes and forbs shake all around us. These sounds and movements in the snow indicate that unstable conditions exist.    

I’m still concerned by the possibility of persistent slab avalanches. This problem is limited to upper elevation shady slopes that had snowcover before Thanksgiving. Many slopes are plagued by large grained depth hoar to the ground, while others sport crust-facet sandwiches with crusts varying in strength and thin very weak layers made up of sugary snow above and in between them. The slab depths where I dug test pits yesterday were in the 16 to 20” range.

Watch for obvious signs of instability like collapsing or woomphing noises, hollow sounding drifts, and shooting cracks.  Reassess your route if any of these signs of unstable snow are present.

Bottom Line:

  The danger is MODERATE on upper elevation north facing slopes steeper than 35 degrees.  Dangerous human triggered avalanches are possible on slopes with weak preexisting snow.

Mountain Weather:

Very cold temperatures will persist over the region today and a flat ridge will begin to move eastward as an active weather pattern continues.  A cold front will move southward over the region tomorrow and tomorrow night bringing a chance for several inches of snow in the mountains. Expect showery conditions on Friday and another somewhat dry storm will affect mainly the Central Bear River Range near the Idaho State Line late Saturday. There’s a looming chance for a bigger storm and a deeper trough in the middle of next week.

General Information:

            The 4th Annual Pray for Snow Fundraiser/Party Friday night was a big success!  Thanks for showing your support.

Check out photos of avalanches in the Logan Area on our images page.

Go to the Avalanche Encyclopedia if you have any questions about terms I use in the advisory

Please e-mail backcountry observations to me at [email protected] or leave me a message at 755-3638. 

The information in this advisory is from the U.S. Forest Service, which is solely responsible for its content.  This advisory describes general avalanche conditions and local variations always occur.