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

Wednesday December 26, 2007

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 Wednesday December 26^th, and it’s 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 Simmons Flexi-ski.

Current Conditions:

It’s currently -3 degrees at the Campbell Scientific weather station at 9400’ on Logan Peak, and a southwesterly wind picked up overnight, now averaging close to 20 mph with gusts in the 30 mph range. It’s 5 degrees at the Tony Grove Snotel site with 42 inches of total snow on the ground.

Avalanche Conditions:

Tragically, Utah’s second avalanche fatality of the season occurred yesterday in the backcountry east of Oakley. A local snowmobiler was killed while riding in his backyard mountains. This accident and continued productive results by avalanche control teams at Utah ski resorts highlights the tricky nature of our current snowpack. The common theme is large deadly slabs releasing on weak or faceted snow from early in the season.

In the Bear River Range, I continue to receive reports of large audible collapses and poor test results from across the region. In the last week tons, of new snow has stacked up on preexisting weak layers. The snowpack hasn’t had enough time to adjust to the additional weight, and more is coming today. Triggered avalanches remain probable on slopes that did not naturally avalanche last week. Soft and stiffer slab avalanches consisting of last week’s and today’s snow in the 3 foot deep range are possible at upper elevations.

Avalanche problems are likely to be exacerbated today by high precipitation rates and wind drifting. The Christmas Eve storm packed strong winds, so you’ll have to deal with the effects of previous as well as ongoing drifting. Be on the lookout for signs of vertical cross-loading around terrain features like rock bands or sub-ridges and in gullies. Pay attention to obvious signs of instability like recent avalanches on similar slopes, collapsing or woomphing noises, cracking, or hollow sounding snow, and be willing to reassess your route.

Bottom Line:

Today there’s already a CONSIDERABLE avalanche danger at upper elevations in the backcountry. Triggered avalanches are probable on some slopes steeper than about 35 degrees. Significant snowfall in today’s forecast means avalanches will be even more likely and the danger more widespread by afternoon, especially on wind drifted slopes facing northwest through southeast. Natural avalanches may occur in some areas. Those without avalanche training and experience should stay well clear of steep slopes and avoid obvious avalanche paths or run-out zones.

Mountain Weather:

The next car in a train of productive Pacific storms will roll through the region today. This one features very cold air and plenty of moisture. Expect 10 to 14 inches accumulation by late tonight. We’ll get a bit of a break tomorrow evening before warm advection snowfall resumes in a productive northwesterly flow. Looks like a high pressure will take over the pattern next week.

General Information:

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.