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

Monday, December 25, 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 Monday, December 25, 2006 and it’s 7:30 in the morning.

Current Conditions:

Skies are partly to mostly cloudy this morning with mountain temperatures in the mid 20’s while colder air has filtered into the drainages and basins. The westerly winds finally calmed down by about mid-morning, but have since ramped up somewhat overnight and are now blowing 20-30mph with a few gusts into the 40’s. Snow surface conditions are well described as ‘variable’, but it’s worth getting out all the same.

Snowpack and Avalanche Conditions:

Yesterday’s forecast verified nicely with two unintentionally triggered slides, a few remotely triggered slides (see flash animation approximation in the encyclopedia), and some 18” hard slabs releasing from explosive testing. All were in somewhat exposed, drifted terrain above about 9200’ on north through east facing aspects, with consistent reports coming in from the Cottonwoods, the Park City ridgeline, and the Brighton periphery. A couple shallow naturals released in the wee hours as well. One skier near Scott Peak along the PC ridgeline had a close call after he jumped off a cornice and triggered a 10-16” by 100’ wide soft slab. The avalanche carried him for 20’ before he arrested onto the bed surface. That’s not all. After skinning back up the ridge, he then remotely triggered the east bowl 6-12” deep and 75’ wide, running over 300’ vertical. Back north along the ridgeline in the Canyons backcountry, another likely remotely triggered slide pulled out over a foot deep, pulling out low in the starting zone. This would be worth investigating.

All were the direct result of the wind loading with most, I suspect, failing on the weak faceted snow formed on the snow surface prior to Thursday night’s skiff of new. With this structure, these drifts can be slow to settle out and I’d expect some of them to remain sensitive today. Trigger-able hard slabs and a snowpack structure that supports avalanches being triggered at a distance warrant extreme caution. The usual bag of mitigation techniques don’t always work. It should also change what you consider to be ‘safe terrain’, especially if you can trigger slides from the flats onto slopes above you or on slopes not directly under you.

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

The avalanche danger remains MODERATE at mid and upper elevation wind drifted slopes steeper than 35 degrees. The danger will be most pronounced on north to east and southeast facing slopes, but be mindful of any fresh wind drifts from terrain channeling. It will still be possible to trigger avalanches at a distance today. Out of wind-affected terrain, the danger is mostly LOW.

Mountain Weather:

Clouds will continue to stream into Utah ahead of what looks to be a pretty good storm for mid-week. Temps will rise to near 30 degrees at 10,000’ and into the mid-30’s at 8000’. The westerly winds will blow 20-25mph with higher averages along the most exposed ridgelines. The Pacific storm will move in late Tuesday and snowfall should persist into early Thursday with 12-18” possible.

Announcements:

Yesterday, the Wasatch Powderbird Guides flew in AF and will try to head back there, Snake Creek, and the Cascade ridgeline today.

The Rescue Training Center at the Canyons Resort is up and running now at the top of the gondola.

Listen to the advisory. Try our new streaming audio or podcasts

Our new, state wide tollfree hotline is 1-888-999-4019.
(For early morning detailed avalanche activity report hit option 8)

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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.

Brett Kobernik will update this advisory by 7:30 on Tuesday morning, and thanks for calling.