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

Sunday January 6, 2008

Hello and good morning, this is Toby Weed of the Utah Avalanche Center with your Logan Area backcountry avalanche and mountain weather advisory.  Itís Sunday January 6th, and itís about 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 Avalanchetools.com.

†††††††††††† Current Conditions:

As the next part of this weekendís storm brings more snowfall into the region, the National Weather Service has continued a Winter Storm Warning through this evening. ††At the CSI weather station on Logan Peak itís currently 15 degrees, and a southwest wind picked up in the last couple hours.Currently reading averages over 30 mph with gusts near 50 mph.Warm advection snowfall started early this morning in the mountains, and thereís 58 inches on the ground at the Tony Grove Snotel with a couple of new.Should be a snowy day in the Bear River Range, with 10 to 12 inches of snowfall forecast at 8800í by dinertime.

††††††††††† Avalanche Conditions:

We have reports of a few fairly large natural avalanches in the Central Wasatch Range and ski areas report some sizable explosive triggered avalanches.I could see evidence of some natural avalanches on the east side of the Wellsville Range yesterday, but have not seen or been notified of any other local action. Iím quite concerned by shady lower and mid elevation slopes plagued with recently formed depth hoar near the ground.Today, another nice shot of snow is overloading these slopes. Lower elevation drifting may be the wildcard here.

Periods of heavy snowfall could bring a significant additional load to slopes in the region where this weekendís new snow didnít bond well to the old weak snow surface. Soft slab avalanches consisting of new snow up to 2 feet deep are possible on many steep slopes.In terrain exposed to southwest and west winds, wind-drifting of the new snow will exacerbate the loading problem and fresh wind slabs sensitive to your weight are a good bet.

Significant loading by wind and snowfall may lead to large avalanches including old snow on slopes in the Central Bear River Range that didnít slide last week. We have not yet seen a significant natural cycle in the Southern Bear River or the Wellsville Ranges and given the many existing weaknesses, there may well be slopes sitting in a delicate balance, only needing a little more weight to avalanche. Likely trigger spots include rocky or generally shallow areas, like upper elevation slopes scoured by previous north winds.††Watch for the dangerous combination of depth hoar and recent drifting at mid and lower elevations.

†††††††††††††† Bottom Line:

Overall, the danger on steep slopes in the backcountry today is CONSIDERABLE. Today avalanche training and experience are essential for safe backcountry travel.Dangerous triggered avalanches are probable on slopes with significant deposits of new or wind-drifted snow steeper than about 35 degrees.Heavy snowfall and continued wind-drifting today may cause the danger in some areas to rise to HIGH, and spontaneous large natural avalanches are not out of the question. Avoid travel in avalanche terrain and stay off of and out from under steep slopes and obvious or historic avalanche paths.

Mountain Weather:

A strong Pacific storm will bring more heavy snowfall to the region today, and a moist westerly flow will continue well into next week.10 to 12 additional inches of accumulation are possible today, with another 8 or so tomorrow.Heaviest periods of snowfall will occur around midday.Winds today will be from the southwest until shifting from the west this afternoon.Expect an active weather week to come with lots more opportunity for snowfall in the mountains.

General Information:

I will give a free avalanche awareness talk for snowmobilers at Renegade Sports on Thursday January 10th at 7:00.

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.

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.