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”

AVALANCHE ADVISORY

Sunday, December 30, 2007 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 Sunday, December 30, 2007 and it’s about 7:30 am.

Current Conditions:

It’ll be a different day out there boys and girls. Increasing westerly winds and additional snowfall pushing storm totals to nearly 2’ in the Provo, Ogden, and Cottonwoods will make for a very active day in the backcountry. Overnight snow totals are 5-10”, and densities remain light, but with an upward trend during the storm. The winds increased yesterday afternoon and again this morning, as ridgetop winds are now blowing 20-30mph with gusts near 50 from the west southwest. Temperatures continue to climb into the mid to upper teens and will likely reach to near 20 degrees prior to the cold front expected around noon.

Avalanche Discussion:

Active and widespread sluffing was the rule yesterday with soft slab development in the afternoon in wind affected areas. A glide avalanche (more info-encyclopedia) released in upper Broad’s Fork and one backcountry skier reported triggering a 1-2’ deep 20’ wide pocket above Lake Desolation on a steep northeast facing slope at 9500’. I would expect those to be commonplace today.

Additional snowfall, rising temperatures, and blowing winds has created an unstable upper snowpack. Naturals are likely in the upper elevations with the increasing winds and during periods of high snowfall rates. Cornice development will be impressive, and those venturing onto slopes steeper than 35 degrees will get immediate feedback from the widespread instabilities. Ski cuts and cornice drops will be very effective here. I do not expect large catastrophic avalanches today, but rather widespread sensitive soft slabs on any wind drifted slope at all elevations.

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

The danger is HIGH on any wind drifted slope steeper than about 35 degrees. Natural avalanches and human triggered avalanches are likely. High precipitation rates and graupel with frontal passage will ensure a CONSIDERABLE danger even in the storm snow.

There is also an isolated MODERATE danger on steep, shady slopes facing northwest, north and northeast, above about 9,500’, where it is possible to trigger a deep, dangerous slide releasing near the ground.

Mountain Weather:

We should see intermittent snowfall today prior to frontal passage, with additional bursts of snow during and after it moves through. An additional 8-12” is likely in areas favored by a west to northwest flow today. Winds will continue to blow 25-35mph along the ridgelines and shift to northwest in the early afternoon. Temperatures climb to near 20, then drop again toward the low single digits tonight. Snow should start to taper off tomorrow morning with flurries expect through the morning. Heights and temperatures rise through the early part of the week ahead of a system of wet and windy storms Thursday through the weekend.

Announcements:
Yesterday the Wasatch Powderbird Guides did not fly due to weather. Today if the weather allows they will be in Days, Silver, Cardiff, Grizzly Gulch and American Fork. For more information, call them at 801-742-2800.

For an avalanche education class list, updated 12/22/07, click HERE.

If you want to get this avalanche advisory e-mailed to you daily click HERE.

The UAC has temporary job openings for doing avalanche outreach in more rural areas. Click HERE for info.

UDOT highway avalanche control work info can be found HERE or by calling (801) 975-4838.

Our statewide tollfree line is 1-888-999-4019 (early morning, option 8).

For our classic text advisory click HERE.

If you’re getting out and see anything we should know about please let us know. You can leave 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 Monday morning.