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, Saturday January 26, 2008   

Hello and good morning, this is Toby Weed of the Utah Avalanche Center with your Logan Area backcountry avalanche and mountain weather advisory.  This advisory is brought to you in part by the Friends of the Utah Avalanche Center in Logan with help from Import Auto.

  We are issuing an Avalanche Watch for Sunday through Monday night for the mountains of Northern Utah and the Western Uintas.  A powerful Pacific storm system will impact the region.  Strong winds and heavy snow will likely create dangerous avalanche conditions in the backcountry for Sunday and Monday.   Before traveling in the backcountry, check for the latest updates throughout this storm period. 

Current Conditions:

Today will be the calm before the storm.  Should see plenty of sunshine, and a gradually strengthening southwest breeze will usher in warmer temperatures.  It’s already a balmy 15 degrees at 9400’ at Campbell Scientifics’ Logan Peak weather station, and there’s a 20 mph west wind with gusts in the upper 40s.  The Tony Grove Snotel reports a few inches of new snow with ½ inch of water equivalent gain in the last 24 hrs, and there’s 70 inches of total snow on the ground.   You can find good powder conditions in the backcountry, especially in sheltered terrain out of sustained direct exposure to the sun.

Avalanche Conditions:

I triggered a wind slab avalanche on Thursday near the summit of Big Baldy in upper First Waterfall Hollow.  The 50-60’ wide by 1’ deep avalanche involved stiff freshly drifted snow deposited overnight on small grained sugary snow called near surface facets.  Yesterday, strong southerly winds and blowing snow drove me out of the high country in search of shelter.  On my way down, I caused extensive surface cracking, which indicates that the few inches of new snow is not sitting very well on the old.  Earlier in the week we noted widespread frost or surface hoar crystals on the snow surface, and the development of weak sugary snow called facets in the upper layers.  Yesterday’s few inches of fresh snow nicely capped these weaknesses.  From the Wasatch backcountry and ski areas from the Provo to the Ogden Mountains, we’ve received numerous reports of easily triggered wind slab avalanches up to two feet deep in terrain exposed to drifting.

Today you could find some of the same type of wind slab activity on many drifted slopes steeper than about 35 degrees.  The problem is most likely to be found at upper elevations, near ridge tops, and on slopes facing the northern half of the compass.  Slabs will be 1’to 2’ deep and may be quite sensitive, as many formed on weak surface snow.  Watch for smooth chalky looking or hollow sounding drifts on steep exposed slopes and cross-loaded slabs in and around terrain features like gully walls, roll-offs, sub-ridges, and cliff bands.

Bottom Line:

There’s a MODERATE danger in the backcountry, and you might trigger wind slab avalanches on drifted slopes steeper than about 35 degrees at all elevations.  Pockets with a CONSIDERABLE danger probably exist on steep upper elevation slopes with significant deposits of wind drifted snow, especially on slopes facing the northern half of the compass.  Use good snow assessment and safe travel techniques to minimize your risks.  Expect the danger to rise significantly tomorrow with heavy snowfall and strong winds in the forecast.

Mountain Weather:

Today will be mostly sunny and warmer, with a gradually intensifying southwesterly wind.  The National Weather Service has issued a Winter Storm Watch for Sunday morning through Monday afternoon.  The winds will begin to pick up significantly overnight tonight.  Expect developing heavy snowfall and strong winds tomorrow in the prefrontal environment, and frontal passage sometime Monday morning.  Expect 1 to 2+ feet of snowfall in the mountains by Monday evening….Another productive storm is forecast for around Wednesday.

General Announcements:

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.

The second annual avalanche awareness ride is Saturday Feb. 2nd and we’d love to see all of you there!  Proceeds help to support snowmobile specific avalanche awareness projects. Details can be found at http://www.avarides.com/

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.