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

Saturday March 25, 2006

Good morning, this is Toby Weed of the Forest Service Utah Avalanche Center with your Logan area backcountry avalanche and mountain weather advisory.  It's Saturday March 25th at 7:00 am.  This advisory is brought to you in part by the Friends of the Utah Avalanche Center in Logan with help from The Trailhead in downtown.

Mountain Weather:

The National Weather Service in Salt Lake City has issued a Winter Storm Warning for the mountains of northern Utah.  The warning extends from 3:00 this afternoon till 11:00 Sunday morning.  Southwest winds will increase throughout the day today, gusting into the hurricane-force category along the highest ridges this evening.  Heavy snowfall is likely with frontal passage in the early evening, and thunder and lightning are quite possible.  6-12 inches of accumulation is forecast, with higher amounts possible in some favored locations. Strong winds will continue during and after the snowfall, shifting around from the northwest later tonight. 

Current Conditions:

You might find some supportable crusts or quasi corn conditions in places this morning.  But last night's surface refreeze was superficial at best, and I expect you'll be punching through in most places.  High southwest winds and increasing cloud-cover will most likely keep things from getting too moist and sloppy today.   After a couple warm days and yesterday's persistent southwest wind, spring powder-like stashes are limited to upper elevation north facing slopes.  Elsewhere, you'll find a wide variety of challenging conditions.  Up at the Campbell Scientific weather station on Logan Peak at 5:00 this morning, it's already 31 degrees and the southerly wind picked up its hourly average to 27 mph.

Snow and Avalanche Conditions:

 Freshly built and forming wind-drifts will be our biggest avalanche concern today.  Sensitive drifts  already began forming yesterday, and one backcountry party reported easily triggering several small ridge-top soft slabs on north facing slopes in the Logan Peak area.  I was a bit surprised to also trigger a sensitive wind slab on a roll at around 7500' in Shumway Canyon in the Wellsville Range.  The very sensitive wind-drift built up yesterday morning on top of a new layer of feathery frost of surface hoar crystals.  When I stepped on the obvious rounded pillow, it broke apart and avalanched, threatening to carry me with it.  The small soft slab avalanche was 1 to 1.5 feet deep and around 30' wide.  It ran around 100 vertical feet and might have been a problem in more dangerous terrain.  Today's increasingly strong winds will find some transportable snow, and drifts will continue to form.  The problem will not just be limited to ridge-tops.  Sensitive drifts will continue to form in and around terrain features like gullies, roll-overs, rock outcroppings, and sub-ridges.  Be on the lookout for such drifts in any area with soft movable snow around, (mid and upper elevation northerly facing terrain).

With strong winds and cloud-cover, I don't think wet avalanches will be very widespread today.  But you might trigger a wet avalanche in sheltered terrain. I am concerned by an insufficient overnight refreeze, and some slopes could get pretty sloppy, especially in areas with shallow snow-cover.  If you find yourself sinking into slushy snow, its time to head home or at least try a different slope.

Bottom Line:

There's  a MODERATE danger and avalanches are possible on wind-drifted or warmth-moistened slopes steeper than about 35 degrees in the backcountry.  With high winds and heavy snow, the danger will rise and become more widespread tonight.

General Information: 

If you're confused by some of our avalanche terms check out the cool new Avalanche Encyclopedia. 

For a list of recent avalanches in  the regional backcountry go to Avalanche List.  Snow nerds, check out the new Snow Profiles page.  Check out our Images Page for pictures of recent local avalanches.

Please send backcountry observations to [email protected] or leave a message at 755-3638, especially if you see or trigger an avalanche in the backcountry. We really want to hear from you, even if you think your observation is unimportant.    The information you provide may save lives...

 Dave will update this advisory Sunday morning by about 7:00.

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.