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

7:30, Friday February 15, 2008

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 February 15th, at 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 The Trailhead. 

Current Conditions:  The snow from Wednesday’s blizzard brought relief to previously scratchy backcountry snow conditions.  Accumulations were a bit spotty across the region, but the Tony Grove Snotel reported picking up 8/10ths of an inch of water in a bit less than a foot of new snow.  Strong winds came around from the east yesterday causing extensive drifting of the light new snow in exposed terrain.  The winds diminished overnight and are now gently blowing from the north at the CSI weather station on Logan Peak, currently averaging a little over 10 mph.  I’m reading 9 degrees at 9400’, and 6 down here in Logan.  You’ll find the best powder conditions on sheltered shady slopes at mid and upper elevations, with dust-on-crust down low and severely wind-hammered conditions in terrain exposed to north and east winds. 

  Avalanche Conditions:  Yesterday morning, an officer from the Cache County Sheriff's Department reported a natural avalanche from late Wednesday that stopped on the flats a few feet from the road near the Green Canyon Gate.  The wind slab avalanche on a northwest facing slope ran on a smoothed-in path over 1000' vertical from a crown at around 6300' and carried a pile of woody debris with it (photos).

Now old news, but also of interest is a large hard slab avalanche on the Richmond Bench, which occurred sometime after last week’s very strong southerly winds.  The large and destructive wind slab avalanche on a northwest facing slope at about 5300’ in elevation stepped down to weak sugary snow or depth hoar near the ground (photos).


Strong easterly winds yesterday scoured the fresh snow from many of the more popular slopes in the region and built stiff drifts in somewhat unusual places.  These, for the most part, bonded fairly quickly to the underlying old snow yesterday.  But some hard wind slabs formed-up on steep upper elevation slopes and in avalanche starting zones with a slick rime-crust or weak frost crystals or surface hoar.  And some of these could still be sensitive to your weight today.  Remember that hard slabs tend to be rather stubborn, meaning they might allow you to get well out on them before releasing….Also, any avalanche could well be long running and  fast moving on well smoothed-in and slick paths… 

Loose, wet avalanches will become possible on sunny slopes at mid and lower elevations as the fresh snow becomes moist from solar warming.


   Bottom Line:  Today there’s a MODERATE danger in exposed terrain at upper elevations, and you could trigger wind slab avalanches on some steep slopes in the backcountry.   You’ll find a LOW danger on most other slopes and in sheltered terrain.  Solar warming will probably cause the danger to rise to MODERATE, with wet avalanches possible on sunny slopes at mid and lower elevations.   Avoid obvious drifts on steep slopes and use good snow assessment and safe travel techniques to minimize your risk.

   Mountain Weather:   The cut-off low responsible for Wednesday’s blizzard is moving through southwestern Colorado and into Arizona leaving us under the influence of a building ridge.  A storm will pass to our north and east tomorrow bringing us a bit of cloud cover and a flake or two.  It looks like we’ll see fair weather and dirty high pressure conditions with storms passing to our east through early next week.  The next productive storm is possible around Wednesday.

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

Check out the images page for photos of some of last week’s avalanches.

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.

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.