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

Special Update

Thursday February 23, 2006

Hello, this is Toby Weed of the Forest Service Utah Avalanche Center with your Logan area backcountry avalanche and mountain weather advisory.  It's Thursday February 23rd 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 Import Auto.

Current Conditions:

Two separate parties described the weather conditions in the same way yesterday.  I met the first party heading down as I was going up.  They looked a bit bedraggled and wind-blasted, like a party returning from an epic dogsled trip to the North Pole or something.  Pointing up the road, the least shell-shocked of the bunch said, "It's nuking up there, just right around the corner."  I found this a bit difficult to believe as I stood in the relative calm of lower elevations.  But as soon as I rounded the corner and came out onto the flats below Tony Grove Lake, it hit me in the face, like an icy atomic blast. Wind-drifted snow already completely filled the tracks of the retreating party who had passed over this very spot only minutes before.  Airborne stinging particles of snow made for complete white-out blizzard conditions.  Two days of strong winds really messed up the snow conditions in most areas above about 8000' and in exposed areas at lower elevations.  Before the winds began, there was lots of nice soft easily drifted powder around.  Now it's all scoured down to hard bare bones and drifted into deep stiff drifts.  The Snotel site at Tony Grove recorded a gain 6/10ths of an inch of water in the last 24 hrs and 1.2 inches in the last 72.   Mountain temperatures have risen somewhat and are about 10 degrees warmer this morning than they were yesterday.  It's 15 degrees atop Logan Peak and 22 at Tony Grove.  The westerly winds calmed a bit overnight, but they're likely to pick up again and continue well into tonight.

Snow and Avalanche Conditions:

 Two days of sustained northwest and west winds formed numerous stiff and sensitive drifts with the new snow and last week's light powder.  Besides loading tons of snow into lee slopes, the wind drifted snow across slopes and built drifts in and around terrain features like gullies and sub-ridges.  On steep slopes these drifts sit in the form of both hard and soft slabs, in many cases resting on weak sugary or faceted snow. Observers in the Ogden Area Mountains report natural and triggered wind-drift avalanches at both lower and upper elevations, and we probably have at least similar snow conditions in this area.  The danger might be more pronounced in the northern reaches of the forecast area (near the Idaho State Line) where winds may have been stronger and more snow fell recently.  Significant or large hard slab avalanches are likely today on exposed upper elevation slopes, and smaller slab avalanches are possible on numerous lower slopes.  You'll find the most danger on slopes facing the eastern half of the compass, but watch for cross-loaded drifts elsewhere.  Watch for steep slopes with significant deposits of stiff feeling or chalky looking snow, and listen for hollow sounding areas.  Pay attention to signs of instability like cracking or audible collapses. Remember, stiff wind-drifts or hard slabs, like those formed in the last couple days, often let you get well out on them before failing.  This means in these conditions an avalanche might break well above you and easily take you with it.

Solar warming could cause a danger of wet avalanches on steep slopes with moist surface snow.  This problem is likely to be a significant concern this weekend as mountain temperatures are forecast to soar above freezing for the first time in a while. 

Bottom Line:

There's a CONSIDERABLE  danger on  wind-drifted slopes in the backcountry, and you could trigger avalanches on many slopes steeper than about 35 degrees.  Significant and dangerous wind slab avalanches could occur and naturals are possible in exposed terrain, especially near the Idaho State-line.  You'll find the most danger and you should avoid steep wind-drifted slopes facing the eastern half of the compass and above about 8000' in elevation.  There's a MODERATE danger, with some avalanches possible on most other steep wind-drifted slopes in the region.

Mountain Weather:

It'll gradually warm up in the mountains, but wind and some snowfall will continue today and tonight.  I expect some clearing and diminishing winds tomorrow and a much warmer weekend.  We'll have to watch out for the initial drastic warming of the cold snow now on the surface.  A warm and productive storm will affect the region next week, beginning on about Tuesday.

General Information: 

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...

   I will update this advisory again tonight.

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. 

National Weather Service - Salt Lake City - Snow.