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

 

 Thursday December 22, 2005                     

Hello,  this is Toby Weed of the Forest Service Utah Avalanche Center in Logan.  Itís Thursday December 22nd at 8:30 pm.   This advisory is brought to you in part by the Friends of the Utah Avalanche Center in Logan, with help from Backcountry Access Inc.

Mountain Weather:

  During the day today, the Tony Grove Snotel site at 8400' picked up 4 or 5 inches of snow containing 7\10s of an inch of water.  Early this morning, southwesterly winds On Logan Peak averaged in the 30s with much higher gusts.  Tonight they're still out of the southwest sustaining averages in the mid-twenties.  The temperatures are still unseasonably warm, with the Campbell Scientific weather station at 9500' currently recording 28 degrees.  Under a Snow Advisory tonight, slopes above 8000' around Logan are forecast to pick up another 6 inches or so of heavy snow before noon on Friday.  Westerly winds should pick up a bit overnight and continue in a sustained state through at least midday.  The Holiday weekend should be pleasant in the backcountry, with only partly cloudy skies and mild daytime temperatures.  The next chance for a bit of snow comes right after Christmas.

Current Conditions:

A few inches of heavy snow went along way toward improving backcountry conditions.  The horrible rain or rime-crust that wasted all the powder even at high elevations on Tuesday froze-up last night, and it now supports your weight if you're on a sled or boards.  But if you try to stand in it with just your boots on, you sink knee deep into the soft cold snow underneath.  I found generally easy traveling and enjoyable turning conditions today above the rain/snow line at about 8000'.  The heavy new snow and the now buried rime-crust allow your sled to float nicely while in motion, but if you bog down and start spinning your track you'll quickly dig down into the buried cold powder and sugary old snow.  Friday looks like one of those days where you will be able to ride almost anywhere if you can keep your speed up, but if you dig-in and get stuck, you're gonna need some help or a bit of time with your shovel to get back on top.

Avalanche Conditions:

 The widespread rain/rime-crust that formed on Tuesday and today's cooling temperatures with cloud-cover and wind at upper elevations locked-up the buried instabilities in the snowpack. But, this morning's storm built sensitive new drifts and bigger cornices in exposed terrain with the sticky thick snow. Today on small test slopes, I cracked out a couple small wind-slabs running on Tuesday's crust. Tonight's impulse will undoubtedly continue the drifting process, and freshly formed wind-slabs could be a foot or two deep on some slopes by morning. 

I don't think we'll get enough additional weight with tonight's storm to reactivate the now-buried weak layers formed during last week's cold weather, but some steep slopes could prove me wrong.  Last week a few inches of super light and very cold snow buried and preserved the weak re-crystallized surface snow and sparkly frost crystals that had formed across many slopes.  On some steep slopes in the region, you might trigger deeper slab avalanches, running on sugary or faceted snow.  Steep slopes above 8000' facing northwest through east with shallow overall snow-cover and significant deposits of wind-drifted snow are the most suspect. 

Bottom Line:

On Friday in the backcountry, you'll  find a MODERATE danger of newly formed wind-drift avalanches on slopes steeper than 35 degrees with significant deposits of wind-drifted snow.  You also could find a MODERATE danger of deeper slab avalanches running on buried weak layers on steep slopes above 8000' facing north through east with significant deposits of wind-drifted snow and shallow overall snow-cover. 

 

General Information: 

 For a list of our upcoming classes and awareness talks, go to our education page

Snow nerds, check out the new Snow Profiles page.

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

  This advisory will expire on Friday night, but I will update it again on Saturday morning by 7:00.

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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