Wasatch Cache National Forest
In partnership with: Utah Division of State Parks and Recreation, The Friends of the Utah Avalanche Center, Utah Department of Emergency Services and Homeland Security and Salt Lake County.

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AVALANCHE ADVISORY

Thursday, January 31, 2008 7:30 am
Good morning, this is Evelyn Lees with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory. Today is Thursday, January 31, 2008 and its about 7:30 am.

 

Special Avalanche Advisory:

Highway avalanche control work will close Little Cottonwood for a while starting at 6:45 am, and Big Cottonwood will have intermittent closures starting around 7:45 for explosive control work in Argenta, Kessler, Stairs and Circle All.

 

Current Conditions:

Under partly cloudy skies, folks are digging out from the latest round of snow. Storm totals from Ogden south through Provo ended up in the 18 to 28 inch range, with densities around 6%. Temperatures are subzero at the 10,000 foot level once again this morning, and the winds are blowing anywhere from northwest to southwest, with speeds in the 10 to 15 mph range, and gusts in the 20s. Winds across the most exposed terrain are gusting into the 40s. Density inversions, wind drifts and sheer depth made trail breaking and turning difficult yesterday, but hopefully overnight settlement will ease these problems, especially in wind sheltered terrain.

 

Snow and Avalanche Discussion:

Yesterday, there was a widespread natural avalanche cycle in the early morning hours, coinciding with the high precipitation rates. Loose snow sluffs and shallow soft slabs occurred on all aspects and elevations. The snow continued to be sensitive to ski cuts and explosives throughout the morning, with the new snow soft slabs running far and fast. There was only one report of a slide breaking into old snow in upper Little Cottonwood, though poor visibility and travel conditions kept observations to a minimum.

 

The greatest avalanche concern today will be any recent drifts of wind blown snow, which will be easy to trigger on steep slopes. These sensitive drifts will be most widespread on exposed, upper elevation terrain facing the east half of the compass, though watch out for crossloading and drifting around mid slope breakovers and other terrain features on a variety of aspects and elevations. Also be very alert for any increase in wind speeds this afternoon there are acre feet of low density snow available for transport, and if the winds pick up where you are, they will rapidly drift the snow, and spontaneous slides may be possible. Out of the wind affected terrain, many of the new snow instabilities have settled out, though sluffing and soft slabs are still possible, and could be large enough to take you for a ride in continuously steep terrain.

 

Field work shows that not all the near surface facets, surface hoar and weak crusts were blasted away by Sundays winds. So in isolated steep terrain, it may be possible to trigger a deeper slide, taking out the snow from two or more storms. Pockets of these weaker snow layers may be most widespread on wind sheltered, protected slopes.

Bottom Line for the Ogden, Salt Lake, Park City and Provo area mountains:

The avalanche danger is CONSIDERABLE on steep, wind drifted slopes, where human triggered avalanches are probable and natural avalanche possible. These wind drifts will be most widespread along the higher ridgelines. Other slopes steeper than about 35 degrees have a MODERATE danger, where it will be possible to trigger shallow soft slabs and sluffs. Avoid terrain traps such as gullies and roads or trails below steep banks where even a sluff could pile up snow deep enough to bury a person.

 

Mountain Weather:

This morning will be a welcome break in the action, though the next storm, poised off the northwest coast, will be here by evening. Temperatures today will warm into the upper teens at 8,000 and the low teens at 10,000. The winds are shifting to the west southwest, and will slowly increase into the 15 to 25 mph range, with exposed terrain having gusts into the 40s by afternoon. Clouds will increase this afternoon, with light snowfall possible, especially north of I-80. A foot of snow is expected overnight, with additional snow on Friday. A brief break Saturday will be followed by another solid snow event, perhaps of less intensity but longer duration, starting on Sunday.

Announcements
Yesterday,
Wasatch Powderbird Guides did not fly, and if they can fly today they will be in Cardiff, Days, Silver, Grizzly, Lambs, American Fork and White Pine. For more detailed information please call (801) 742-2800 or go to their daily blog.

The second annual avalanche awareness snowmobile ride is Saturday, February 2nd and proceeds will help support snowmobile specific avalanche awareness projects. Details can be found at http://www.avarides.com/

 

Backcountry Awareness Week is February 8-10th, featuring a Friday night fundraising dinner with guest speaker David Oliver Relin, author of the New York Times bestseller Three Cups of Tea: One Man's Mission to Promote Peace...One School at a Time and avalanche awareness clinics on Saturday and Sunday, all held at Snowbird.  For more information, call 933-2147 or go to http://www.avalanche.org/~uac/fuac-events.htm.


If you want to get this avalanche advisory e-mailed to you daily click
HERE.
UDOT highway avalanche control work info can be found by calling
(801) 975-4838.
Our statewide tollfree line is 1-888-999-4019 (early morning, option 8).

The UAC depends on contributions from users like you to support our work.  To find out more about how you can support our efforts to continue providing the avalanche forecasting and education that you expect please visit our Friends page.

If you see any avalanches or interesting snow conditions, please leave us a message at
(801) 524-5304 or 1-800-662-4140, or email us at [email protected]. (Fax 801-524-6301).

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.

Bruce Tremper will update this advisory by 7:30 on Friday morning.