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

Tuesday February 21, 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 Tuesday February 21st at 9:00 pm.  This advisory is brought to you in part by the Friends of the Utah Avalanche Center in Logan with help from the Trailhead.

Current Conditions:

An arctic northwest wind blasted the high country for several hours today, and it found lots of cold powdery snow to blow around.  I was worried about falling snags as I watched large firs rocking back and forth in the constantly roaring wind.  The mercury barely moved today, staying below 5 degrees on Logan Peak and in the low teens at Tony Grove.  With the wind-chill and the tiny stinging wind-borne snow crystals,  I felt like I was back climbing in the Alaska Range.  The Snotel site at Tony Grove  recorded 2/10ths of an inch of water in a couple inches of fine-grained snow.  Unfortunately, the wind was strong enough even at mid-elevations to damage the fine powder on lots of slopes that were in great shape yesterday.  It looks like it'll be quite cold again on Wednesday with a couple more inches of snow possible overnight tonight and again during the day.  Mountain temperatures will plummet well below zero on Wednesday night.

Snow and Avalanche Conditions:

 Today's sustained northwest winds formed numerous stiff and sensitive drifts with the light powder in  terrain exposed to this wind direction.  I found much more extensive drifting today than in the past few days and more potential for avalanches. The wind drifted snow across slopes and built drifts in and around terrain features like gullies and sub-ridges.  On some slopes, the drifts built up on a layer of well-preserved sugary or faceted snow that was on the surface a week ago.  These drifts could sit in a sensitive state for a while, awaiting your intruding weight to cause an avalanche.  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 today, 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. 

 (2-22-06 am)  Observers reported a couple significant human triggered and natural hard slab avalanches at upper elevations in the mountains near Ogden and there's a good chance we could find similar snow conditions on some exposed upper elevation slopes around here.

Bottom Line: (updated 2-22 @ 7:15 am)

There's a MODERATE danger in the backcountry, and you could trigger avalanches on wind-drifted slopes steeper than about 35 degrees.  You'll still be able to find stable snow conditions on lots of steep slopes in sheltered terrain.   However, with persistent strong northwest winds continuing, a CONSIDERABLE danger may exist in places, and some sizable triggered or natural avalanches are possible on north through southeast facing slopes steeper than about 35 degrees and above around 9000'.

Mountain Weather:

  Minor disturbances embedded in a cold northwesterly flow will continue to affect the region for next couple days.  No major weather events, but a couple inches of snow are possible in each of the next several 12 hr forecast periods.  Westerly winds will remain in the moderate category, and temperatures will stay pretty cold though the week.  Next weekend should be mostly fair, at last with warmer temperatures.

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...

 This advisory will expire Wednesday night.  I will update it again on Thursday night.

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.