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.

                        The Utah Avalanche Center Home page is: http://www.avalanche.org/~uac/

                                          (click on) Utah Avalanche Center in Logan for our home page           

Logan area Avalanche advisory

Sunday February 18, 2007:

  Hello and 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 Sunday  February 18th, and it’s 7:20 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 of Providence.

Avalanche Conditions:

Tragically, avalanches killed three Utah snowmobilers in the backcountry yesterday.  News of the fatalities in separate accidents in Wasatch County, Sevier County, and Bonneville County Idaho, is just coming out this morning (link to KUTV's Web coverage).  Several other reports of unintentionally triggered avalanches in Utah are filtering in, including a few involving very experienced riders and skiers, some taking serious rides.  I examined evidence of widespread natural and triggered slab avalanches from Thursday night and Friday in the Tony Grove Area.  All this drives home the fact that widespread dangerous avalanche conditions exist across the regional backcountry this weekend.   We use the term CONSIDERABLE to describe the current level of danger in the backcountry. This means that avalanches are probable with human triggers.  Unfortunately, somehow it seems we're not getting the word out.

In the Logan Area, with Thursday night's heavy snowfall, significant slabs built up on existing sugary weak layers. Many slopes that did not naturally avalanche could be now sitting in a volatile balanced state.  In addition to causing a danger of moist point-release avalanches on sunny slopes, very mild daytime temperatures today could create an increasing danger of slab avalanches.  Warmth speeds up the creep rate of the slabs often causing natural avalanches, or worse, increases sensitivity to triggering...  I know most of you are now carrying and have practiced extensively with your beacons, probes, and shovels, but you need to remember not to expose more than one person at a time to avalanche danger on steep slopes.  I watched in horror yesterday several times as two or sometimes three of you at a time tested obvious avalanche starting zones... Remember, your buddy can get his sled unstuck himself and without your help on a steep slope.

Current Conditions:

Riding and turning conditions are improving in the backcountry, but it's a far cry from powder snow.  Hardly seems worth it to risk the dangerous steep lines when the snow is fast and you can have fun on low angled terrain.  You can ride anywhere, but bogging down and spinning your track into unconsolidated sugary snow is a good possibility on steep shady slopes.  There are 62 inches of total snow on the ground at the Tony Grove Snotel site, which is only 68% of average for the date.

Bottom Line:

Very mild daytime temperatures today could cause a more widespread danger of both slab and moist point-release avalanches, and some may naturally occur in the heat of the day.  There's a CONSIDERABLE avalanche danger in the backcountry, and you could trigger dangerous slab avalanches on any slope steeper than about 35 degrees with recent deposits of drifted snow.  The danger is greatest in areas that picked up significant new snow, above about 8000' in elevation, and on slopes facing north, northeast, and east.  Elsewhere the danger is MODERATE, with avalanches possible on some steep slopes at lower elevations and on some west and southwest facing slopes. 

Mountain Weather:

   Clouds will thicken this afternoon ahead of a splitting Pacific storm.  Up north we'll see a decent shot of snowfall overnight, with southwest winds and 8 to 10 inches of accumulation forecast by Monday morning.  The weather pattern for next week looks unsettled and mild, with the next shot of storminess possible on around Thursday.

 General Information:

Go to the Avalanche Encyclopedia if you have any questions about terms I use in the advisory.  Check out the recently-released Media Page, which shows the current and forecast danger for our coverage areas across the state.

The Utah Avalanche Center compiled a good collection of photos from this week's avalanche cycle in the Wasatch Range.  Click here to visit this season's photos.  Check out photos of recent avalanches in the Logan Area on our images page.

Please send me an e-mail at [email protected] or leave me a message at 755-3638 if you see evidence of recent avalanche activity or avalanches in the backcountry.  The information you provide may save lives...

  This advisory will expire on Monday morning.  I will update it again on Tuesday evening.

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.