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, Wednesday February 20, 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 Wednesday February 20th, 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 Avalanchetools.com.

Current Conditions: Even lacking the fresh powder we’ve become so used to this season, most people I’ve talked to report at least finding some form of “fun” snow in the backcountry. You don’t have to get too far out of the Valley to escape the smog and you can find supportable, sun-softened snow on many low elevation slopes. Yesterday in fast snow conditions, we were able to have a lot of fun on very low angled terrain. With some knowledge of the local terrain or willingness to explore, you can find reasonably good reconstituted, shallow powder snow-like conditions on sheltered slopes facing the northern third of the compass… I didn’t find any yesterday, but observers report finding secret stashes of soft, “loud” snow on north facing slopes at all elevations. Supportable snow conditions allow for riding “anywhere you want to go.” Expect some cloud cover to build in today, and temperatures at 8000’ to warm to near thawing. Definitely under the influence of a temperature inversion, I’m reading 21 degrees at 9400’ at the CSI weather station at Logan Peak and 3 down in murky Logan City. Southwest winds are averaging around 20 mph along the highest ridges this morning.

Avalanche Conditions: It was fairly quiet avalanche-wise in the Logan area over one of the season’s most popular backcountry weekends. I’ve received only a few reports; a small, intentionally triggered wind slab on the steep north side of White Pine Knob and a near miss when a rider triggered a bus-sized cornice-fall on Castle Rock just south of Naomi Peak while trying to get a view down his intended line. Go to the “photos” link for images of some other natural action from last week.

Cloud cover may trap solar heat today. The “greenhouse” affect might come into play in sheltered mid-elevation terrain and wet avalanches may become possible around midday on a few warmth softened slopes. The problem today could include moist snow on warming shady slopes. Remember to leave or reassess your route if the snow on the slope you’re on or below gets moist and sloppy.

You might trigger older wind slabs or large cornice-falls on a few very steep slopes, especially at the highest elevations. Some wind slabs formed in avalanche starting zones plagued by notoriously persistent weak layers made up of frost crystals or surface hoar and/or associated with a slick rime or sun-crust. Remember that hard wind slabs tend to be rather stubborn, meaning they might allow you to get well out on them before releasing.

Bottom Line: Overall today you’ll find a LOW danger in the backcountry and avalanches are generally unlikely. A low danger does not mean no danger and you might trigger wind slab avalanches or large cornice falls on a few very steep slopes in exposed upper elevation terrain. Midday warming could cause the danger of wet avalanches to rise to MODERATE on very steep slopes in a few mid-elevation pockets. Use good snow assessment and safe travel techniques to minimize your risk.

Mountain Weather: A storm moving out of Central California and passing to our south will bring cloud cover and a chance for a little snowfall late today and tonight, but don’t expect much if any accumulation. Light southerly winds will shift around from the west by this evening. Stronger Pacific impulses should break down the inversion and bring widespread snowfall to the region, with a couple nice shots of snow forecast for the weekend. The first, starting up around midday Friday and lasting into Saturday morning and the second, somewhat stronger wave, expected late in the day on Sunday.

General Announcements:

Upcoming avalanche class: February 29th-March 1st, Avalanche Basics, USU Outdoor Recreation Center, Friday February 29th, 6:30p,  Field Session Saturday March 1st, 9:00a.  ($35, Please register in advance with the ORC.)  For more information contact [email protected].

Check out the images page for photos of some of this season’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.

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.