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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Sunday, January 06, 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 Sunday, January 06, 2008 and it’s about 7:30 am.  An Avalanche Warning continues today for the Western Uinta Mountains as the danger remains HIGH.  Craig’s advisory for the Uintas can be found here.


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Current Conditions:

It’ll be old news soon, but it’ll be awhile before I forget yesterday’s storm.  Let’s look at the numbers: Little Cottonwood 17”/4” h20, Big Cottonwood 21”/4.56”h20, Park City areas averaging 18”/2.57”h20, Ogden mountains 12”/1.69”h20, Logan mountains 15”/1.6”h20, and the Provo mountains 8”/1.2”h20.  Hourly precipitation rates of .54 and .49 at the Alta Collins station was unprecedented.  Accompanying southwesterly winds averaged 40-45mph with gusts to 70mph.  Clearly, most of this was graupel (more on this later), with a few inches of fluff on top after the wind shift in the morning.  Skiing and riding was excellent – and trailbreaking was like walking uphill in a sandbox.  In the afternoon, the lighting, shadows, and color was brilliant as the storm moved off to the east. 


The next storm is already upon us with snow falling again in the mountains.  Winds have shifted to the southwest and are blowing 25-30mph with gusts into the 40’s.  Temperatures have warmed with the warm front and are in the upper teens and low twenties. 


Avalanche Discussion:

It’s likely that we experienced a widespread shallow natural cycle with the explosive water numbers yesterday, but poor visibility and immediate reloading precluded much in the way of data and observation.  There were, however, some important events in the backcountry, representing our increasingly varied snowpack.  A large full depth natural reportedly broke out ‘wall to wall’ in what’s fondly known as ‘Radar Love Bowl’, just south of Scott Peak along the Park City ridgeline.  It’s a steep east facing slope at about 9800’.  Just around the bend there in upper Big Cottonwood Canyon, an out of bounds skier or boarder triggered a large hard slab avalanche in Hidden Canyon 4-6’ deep and 200’ wide on old faceted snow.  Bruce happened to be in the vicinity and put together a report, found on our photos page here.  My own party collapsed a west facing slope after finding a near-natural in weak faceted snow along the USA bowl/Willows ridgeline in upper BCC.  Control work at the ski areas pulled monsters out up to 8’ -10’ deep on a variety of the easterly, northerly and westerly aspects, with some sympathetic to other releases or shot placements. 


In 1971, Wallace Stegner wrote an American classic called Angle of Repose.  While I think the title refers to a person’s place in life, in snow anyway it has to do with the angle in which snow can sufficiently stick to the slope before falling away.  Graupel, the crystal type that made up the bulk of yesterday’s storm, is notorious for having a low angle of repose, the simple explanation on why many avalanches running on the ball bearings are on lower angled slopes or at the base of cliffs where they’ve bounced down and congregated.  They’re famous for being loose and unconsolidated and we’re likely to see more activity on this layer for the next few days. 


Anytime you hammer the snowpack with this explosive amount of water weight, you’re likely to see large and unusual avalanches.  Snow and the shear strength between the various layers is such a dynamic, ever-changing environment.  And so it was to everyone’s surprise to see a large natural 4’ deep and 150’ wide pull out overnight inbounds in semi-compacted terrain in the lower mid cirque in mid-Big Cottonwood Canyon. Clearly the hammering is over, but the pack is taking time to adjust.  It’ll be worth tip-toeing around again today, with the real potential for triggering large unsurvivable avalanches.  Another foot or more of new snow today coupled with moderate and gusty winds will create another round of sensitive drifts on the steep lee slopes as well. 


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

In areas that received the most snow, the avalanche danger is CONSIDERABLE on all slopes 35 degrees and steeper.  Human triggered avalanches may continue to be up to 4-5’ deep in overloaded terrain.


Mountain Weather: 

We’ll see snow throughout the day with this current system with heavy snowfall rates with frontal passage in the early afternoon.  The Provo and Ogden area mountains will benefit from the southwesterly and westerly flow, but everyone should see at least a foot of snow.  Winds will be 25-35mph from the southwest prior to the cold front.  Temps will be in the upper teens and low twenties.  We’ll continue to see an active storm track through the week. 


Wasatch Powderbird Guides did not fly yesterday, and will not be flying today due to high winds.  For more information, call them at 801-742-2800.

Solitude’s beacon park is now up and running, and ready for use.  It’s FREE and located just off the northwest corner of the lower lot.


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

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.

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