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

December 28, 2006

Hello, this is Toby Weed of the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory.  It's Thursday December 28th, and its 9:00 pm.  This advisory is brought to you in part by the Friends of the Utah Avalanche Center in Logan with help from Simmons Flexi-ski of Providence.

Current Conditions:

You can find nice shallow fresh powder on most slopes in the regional backcountry, with good turning and supportable, ride-anywhere conditions.  Lots of people got out in the Bear River Range high country today, but I could still find plenty of fine fresh snow, and today's generous cloud-cover saved it for tomorrow.  Yesterday, the Tony Grove Snotel site recorded around 6 inches of accumulation containing 6/10ths of an inch of water, and the site at Ben Lomond Peak picked up 1.3 inches of water in 7 or 8 inches of snow.  While conditions are fairly calm in the Logan Canyon Region of the Bear River Range, a strong northeasterly wrap-around wind is raking the high country in the southern part of the forecast zone, with Mt. Ogden showing consistent 40 mph winds and 60 mph gusts.  The wind speed sensor on Logan Peak appears to be rimed up, but it's also showing a northeasterly wind direction.

Avalanche Conditions:

Wind slabs, which formed right after Christmas and are now obscured by half-a-foot of powder, are still causing problems in the Bear River Range.  Today, I came across a wind slab avalanche that was unintentionally triggered shortly before my arrival by a snowmobiler (pictures).  The small hard slab avalanche on a 36 degree east-southeast facing slope failed just above a thin sun-crust in a thin sugary layer containing a few intact frost or surface hoar crystals.  The existence of  this active persistent weak layer and an overlaying stiff wind-deposited slab indicates that there is a lingering danger on similar slopes in the range.  The current strong northeast winds, mainly in the southern part of the region, are building a whole new set of drifts with the fresh snow in somewhat unusual places.  Observers continue to report triggering audible collapses or whumphing noises, most prevalently at mid-elevations on the eastern side of the range.  Others report shooting cracks in ridge-top drifts.  Both are obvious clues, sure indicators of lingering instability.

Bottom Line:

There is generally a MODERATE avalanche danger in the Bear River Range backcountry, with triggered wind slab avalanches possible on slopes steeper than about 35 degrees and above around 8000', with recent or previous deposits of wind-drifted snow. 

At upper elevations, especially in the southern part of the forecast zone, including the Wellsville Range, the mountains above Mantua and the Northern Ogden Valley, and on any steep slope with a recent and substantial deposit of wind-drifted snow, there's a CONSIDERABLE danger.   This means you could trigger wind slab avalanches on many steep slopes and some naturals are possible.   At this point we tell you that avalanche training and experience are necessary for safe backcountry travel.

Mountain Weather:

As our yesterday's storm powerfully wraps back around into an already snow-stricken Denver, a high pressure system will start to build over the Great Basin.  Some light snowfall is possible around the New Year, but it doesn't look like much. Looking ahead; the models are hinting at a pattern change late next week, with a more consolidated and productive westerly flow possibly setting up.

General Information:

The Friends of the Utah Avalanche Center-Logan will present the 3rd annual fundraiser on Friday, January 19th at the Bullen Center in downtown Logan.

For neat pictures of some of this season's avalanche activity visit our Images Page.

These advisories are updated on Tuesday and Thursday evenings and weekend mornings by about 7:00. I will issue an updated advisory Saturday morning.  Logan Area advisories are accessible through the new statewide toll-free avalanche information line at, 1-888-999-4019.

Please send backcountry observations to [email protected] or leave us a message at 755-3638, especially if you see or trigger an avalanche in the backcountry.  I'm a little starved for information from you these days.  Your observations are necessary, and the information you provide may save lives. 

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.