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 advisory

 

 Tuesday, December 13, 2005           

Hello, this is Toby Weed of the Forest Service Utah Avalanche Center in Logan.  Itís Tuesday, December 13th at 8:00 pm.   This advisory is brought to you in part by the Friends of the Utah Avalanche Center in Logan with help from Import Auto at 502W 1400N, the only place to go for all types of automobile repair.

Current Conditions:

With yesterday's warming and today's wind you'll find a wide variety of snow conditions in the Logan backcountry.   You'll find thin sun-crusts on sunny slopes and wind-scoured or drifted-in slopes in exposed terrain.   Even so, you can still find nice re-crystallized snow on shady sheltered slopes, and fairly supportable riding conditions at high elevations.

Cold temperatures, riding a frigid northwesterly wind returned to the high country today.  It's dropped into the lower teens at most stations and down to 4 degrees at the Campbell Scientific weather station on top of Logan Peak. This morning, the station recorded sustained 30mph winds from the southwest. The wind shifted around from the northwest during the day today, and regional Snotel sites recorded a trace to a couple inches of snowfall.  A couple more inches could fall overnight, and tomorrow's forecast high temperature at 8500' is 20 degrees.

Avalanche Conditions:

Recently formed wind-drifts will be your biggest concern in the backcountry on Wednesday.  Today's wind in the mountains was strong enough to build drifts even with the old re-crystallized surface snow.  You might trigger an avalanche on some steep slopes in the region where significant drifts formed.  Be wary of stiff, hollow sounding and chalky looking drifts or hard slabs, especially when they are resting on sugary or faceted snow.  Some wind deposits in exposed terrain could be more than a foot deep by morning.

Cold temperatures and clear nights are perfect conditions for the process called temperature gradient metamorphism, which weakens layers in the snowpack.  Water vapor moves upward through the generally shallow snowpack changing the individual grains of snow into sugary facets.  At lower and mid-elevations, and in areas outside the central Bear River Range, a shallower snowpack means that this process is accelerated.  The shallow snow on some slopes in the region is now almost pure rotten sugar, and it is very weak.  This will probably cause me to worry about deep slab instability in the future when it's buried by a significant slab.

Bottom Line:

There's a MODERATE avalanche danger and you might trigger an avalanche on some recently wind-drifted slopes steeper than about 35 degrees in the backcountry.  On the majority of slopes in the Logan area  there is still a  LOW  danger, and avalanches are generally unlikely. 

Mountain Weather:

Even without much snowfall, today's blast of weather spelled the end of the nasty inversion.  We can breath freely in Cache Valley tomorrow, and with luck we'll be spared the smog for a little while.  We could be back in a more favorable weather pattern, with a hope of snow Friday and Saturday.

General Information: 

The new Trailhead store on 100 N in Logan is now open.  You should come down and check out the selection of backcountry goodies.

The USU Outdoor Recreation Center is offering  a two-day Avalanche Awareness Class with help from the UAC in Logan, beginning at 6:00 on Dec.15th.  For a list of our upcoming classes and awareness talks, go to our education page

Beaver Mountain is now open and conditions are good.

Please send backcountry observations to [email protected], especially if you see or trigger an avalanche in the backcountry.

This advisory will expire on Wednesday night.  I will update it again on Thursday night.

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. 

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