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 17, 2006 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 17, 2006 and it’s 7:30 in the morning.

Current Conditions:

As of 5am, at least in upper Big Cottonwood Canyon and the Park City areas, 9-11” of 8-9% now buries Friday night’s 8-10” of 6%. Little Cottonwood and the Provo mountains received 6-8” thus far, with the Ogden and Logan mountains pulling in 3-4”. The east and southeasterly winds are averaging 20-25 mph, with the most exposed ridges showing winds in the 25-35 mph range. Temps are in the single digits and low teens. Riding conditions have improved in a hurry.

Snowpack and Avalanche Conditions:

Most of the activity yesterday centered around a quick shallow natural cycle in the morning, followed by immediate gratification loose snow and super soft shallow slab activity described as very sensitive.

Today’s issues will be more problematic. The new, higher density snow will likely run on the lower density from the day before, possibly stepping down to some of the older crusts formed late in the week. With weaker snow beneath some of the eggshell crusts, collapse failure above 8500’-9000’ may produce larger, more dangerous slides. Lastly, control work along the Park City ridgeline on Friday pulled out avalanches to the ground in uncompacted terrain, highlighting the fact that the weak snow from late fall and early December hasn’t gone to pasture. Snow pits in the shallower areas have pointed toward this, and the nagging feeling just won’t go away.

When you’re out today, jump in steep test slopes, drop cornices, and anticipate shooting cracks in the new snow. With unusual winds out of the east to southeast, be more cautious as the drifting patterns will be different than what you may be accustomed to. For those without good snow assessment skills, I’d recommend staying on slopes less than 35 degrees, where the danger is less pronounced.

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

The avalanche danger is CONSIDERABLE in upper elevation terrain that has received and will continue to receive the most snow, such as upper Big Cottonwood, Provo Mountains, and along the Park City ridgeline. Areas out of the wind will have a MODERATE danger today for storm snow avalanches.

Mountain Weather:

A cold Pacific storm system will continue to produce snow throughout the day with another 5-8” expected in favored areas. With the upper Low pressure system movingoverhead, it’s difficult to forecast the wind direction and speed (not to mention snow amounts), but I’d guess that winds will rotate south averaging 15-25mph. Temps will remain in the upper single digits to low teens. A ridge builds in for the early part of the week.

Announcements:

If they can get out, the Wasatch Powderbird Guides will be in American Fork and Snake Creek.

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We appreciate any snowpack and avalanche observations you have, so 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.

I will update this advisory by 7:30 on Monday morning.