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.

keeping you on top


Tuesday, January 29, 2008  7:30 am
Good morning, this is Drew Hardesty with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory.  Today is Tuesday, January 29, 2008 and it’s about 7:30 am. 


Bruce Tremper will be giving a free talk at the SLC REI tonight at 7pm called The Science of Avalanches. 


Current Conditions:

Let’s reconstruct the last 30 hours or so.  3-8” of mostly graupel and rimed crystals fell in the early Monday morning hours prior to the cold front, which arrived around 11am.  Lightning and gusts over 100mph preceded, at times, snowfall rates of 3-4”/hour, piling up the snow in a hurry and producing widespread, if relatively shallow, natural avalanching at a variety of aspects and elevations.  Temperatures dropped into the single digits, with many stations dropping to 7 or 8 degrees below zero.  The winds veered back to the northwest with the passing of the cold front, and snowfall favored the Cottonwoods, though much of the range received a good blast of snowfall.  Lingering showers overnight added another 1-3”, pushing storm totals to nearly 2’ in the Cottonwoods, 8 and 16” in the Ogden and Park City mountains, and about 4-6” in the Provo mountains.  The winds refuse to buckle, and have remained strong, blowing 25-35 mph with the most exposed stations suffering hourly averages of 45-55 mph, gusting to 80.  Wind chill temperatures are currently calc’d to -45 degrees Fahrenheit at 11,000’. 


Snow and Avalanche Discussion:

Ski areas and UDOT explosive work produced many new slides in the new snow, with a few pulling out into older layers at the lower elevations on the Park City side of the range. 


Numerous stiff wind drifts up to and over 3’ deep will be scattered throughout the standard starting zones and less obvious areas.  Strong winds ahead of and behind the front will have alternated eroding and loading patterns, so the patchwork of wind effect will be complex and tricky, and likely ill-defined by convention or pattern with respect to aspect and elevation.  The deposited hard slabs will only be stiffened and, in many areas, difficult to trigger due to the colder temperatures, but may be difficult to escape once triggered.  The hard slab phenomenon here may allow multiple tracks or a skier or rider well onto the slope before they trigger the thin spot allowing the slope to fail.  Likely unsurvivable.  Multiple potential weaknesses include the graupel prior to the storm, intra-storm weaknesses, and localized sheets of surface hoar and faceted grains from brief interludes of high pressure last week.  Collapsing and hollow sounds are clues to local instabilities.  Cornices, while stiff, may break back farther than expected.  Slope cuts will likely be ineffective and dangerous and single snow pits will be wildly inconclusive, if wholly unrepresentative. 


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

The danger is CONSIDERABLE on any steep wind drifted slope.  It will be possible to trigger avalanches with severe consequences in localized terrain. For LOW danger, look for protected gladed low angle slopes less steep than 30 degrees that are not underneath or ‘attached’ to adjacent steeper terrain. 


Mountain Weather:

We’ll see some break in the clouds, warming temperatures, and gently backing winds ahead of tonight’s next vigorous storm.  Temperatures at 10,000’ will ‘warm’ to 10 degrees as 8000’ temps push into the low teens.  The mellowing southwesterly winds today will blow 20-30mph, only to increase again ahead of the strong cold front overnight.  12-16” can again be expected in areas favored by a northwest flow, with the Ogden and Provo areas benefiting from the pre-frontal environment.  More Pacific storms are on tap Thursday afternoon and again through the weekend.


Yesterday, the
Wasatch Powderbird Guides didn’t get out.  If weather permits they will be flying in Cardiff, Days, Silver, Grizzly, & American Fork. 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
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.

Evelyn Lees will update this advisory by 7:30 on Wednesday morning.