Wasatch-Cache National Forest:  In partnership with:  Utah State Parks and Recreation, Friends of the Utah Avalanche Center-Logan, and Utah State University College of Natural Resources.

               

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Logan area Avalanche statement

Friday December 14, 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 Friday December 14th 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 Avalanchetools.com.

             Current Conditions:

You’ll find a nice dusting of cold powder in the mountains today, with the Franklin Basin Snotel picking up around 4 inches overnight. The total snow stake up at the Tony Grove site shows around 23 inches on the ground, with 3 new inches of cold smoke.  It’s a bitter 2 degrees at the CSI Logan Peak weather station with chilling northerly breeze at 9400’.  I’ve been getting up into untouched terrain in the last few days and hitting numerous rocks.  It’s possible to find slopes with enough snowcover to do a few turns on, but you have to keep your speed down since the shallowly buried rocks are well hidden in the powdery snow. I’m still riding exclusively on upper elevation roadways and smooth meadows, and I’m still ticking rocks with my skis from time to time.

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:

The weak faceted snow from the early season is slow to heal.  Two people took nasty rides and sustained injuries in separate avalanches in the backcountry near Brighton yesterday. Although no avalanches have been reported in the Logan Area the potential still exists on steep shady slopes at upper elevations.  I continue to trigger woomphing or audible collapses in untouched areas with weak preexisting November snow.  Woomphing indicates that unstable conditions exist. In many areas the only lacking element is a cohesive slab. The generally shallow snowpack may also be held in place by numerous anchors.  I’ve been able to find pockets of stable but barely deep enough snow on west and east facing slopes at high elevations.

The possibility of persistent slab avalanches still looms. 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 snow, and shooting cracks.  Reassess your route if any of these signs of unstable snow are present.

Bottom Line:

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

Mountain Weather:

Very cold temperatures and a few snow showers will persist over the region today as an active weather pattern continues.  A weak ridge will build over the region today and valley inversions will start to build.  A storm system will pass well to our north on Saturday night, bringing a few clouds and a minor threat for a few snow flakes.  The next chance for significant snowfall comes late Tuesday into Wednesday.

General Information:

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

 I'm very interested to know what you're seeing out there.  Please e-mail observations to me at [email protected] or leave me a message at 755-3638, especially if you see or trigger an avalanche in the backcountry. We keep all observations confidential.

This advisory will expire in 24 hours from the posting time.

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.