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.

AVALANCHE ADVISORY

Wednesday, December 21, 2005 7:30am
Good morning, this is Bruce Tremper with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory. Today is Wednesday, December 21, 2005, and it’s about 7:30 am.

Check out our new graphical advisory format. You can update your bookmarks to this link:

http://www.avalanche.org/~uac/newadvisory/advisory.php

We will publish both this text-based advisory as well as the new graphical version so you can choose which one you prefer. Let us know about any formatting problems.

For those of you old enough to remember, Sue Ferguson was the director of the Utah Avalanche Forecast Center before I took over in 1986. She lost a long battle with breast cancer two days ago. Sue was an amazingly intelligent and talented woman who also started The Avalanche Review. We will miss her.

Craig Gordon will give a free avalanche class tonight at the Fire Station in Wanship at 7pm.

The beacon locator park at Snowbird is now open and free to the public. It’s sponsored by Wasatch Backcountry Rescue and Snowbird and located just off the bypass road in upper Little Cottonwood Canyon.

Current Conditions:
We could solve all our energy needs this winter if we could just harness all the hot air expended on cursing the snow conditions these past couple days. One of our most experienced observers described it as “the most super-heinous conditions I have ever experienced.” Another person described the snow as “5-minute epoxy.” The very warm temperatures and wind have made the snow very up side down with a dense, stiff slab on top of the cold, dry snow from Sunday. I wish my stock portfolio looked like the graph of ridge top temperatures these past three days—up, up, up. They will likely peg out around 37 degrees today and much warmer at lower elevations. The snow conditions seem worst on the west side of the Wasatch Range and better on the Park City side and in the Uinta Mountains.

Avalanche Conditions:
There wasn’t a lot of avalanche activity yesterday as the slab was stiff and stubborn. As one friend of mine told me yesterday, “They’re hard to trigger, but if you do, you will feel like Jimmy Hoffa—encased in concrete.” One person kicked a cornice on southeast facing ridge of Renolds Peak in Big Cottonwood Canyon and triggered a 1.5 foot deep, 75’ wide slab in the new snow. Photo There was also a natural avalanche during the storm in the main bowl of Reynolds. A natural avalanche occurred yesterday morning on Pioneer Ridge near the Park City Resort of about the same dimensions on faceted snow, and a natural that occurred during the storm on a southeast facing slope in Willows Photo 1, Photo 2, Photo 3, Photo 4. Most of these were running on the density inversion within the new snow, but occasionally on the weak faceted snow formed during the clear spell. Clear skies overnight have likely made most of these avalanche problems settle out, but there’s still a couple things you will need to pay attention to today:

Lingering slabs still exist on upper elevation steep slopes, especially on the buried layer of weak faceted snow on the northerly through easterly facing slopes. These avalanches will be difficult to trigger, but they will be large and dangerous. They will break 1-3 feet deep and the stiff slab above the weak layer will feel solid and stiff until the whole slope lets go. Fractures will likely break up above you.

Second, very warm temperatures will continue today, which will produce localized wet sluffs and occasional wet slabs at lower elevation slopes that are getting wet and sloppy. Be sure to get off of and out from underneath steep slopes when they get soggy. Clues to instability include rollerballs and point-release sluffs.

Bottom Line:
There’s a MODERATE danger today of lingering slabs on persistent layers of faceted snow on northwest, north, northeast and east facing slopes above 8,500’ steeper than 35 degrees, especially in thin snowpack areas. There is also a MODERATE danger of wet sluffs and wet slabs at elevations below about 8,500’ when the snow gets wet and sloppy.

Mountain Weather:
Today we have a ridge building over us and the ridge top temperatures will spike up to a very toasty 37 degrees by mid day. Down at 8,000’ they should rise to 45 degrees. Skies should be mostly sunny this morning, but we should have increasing clouds this afternoon. Ridge top winds will blow 15-20 from the northwest, switching to the southwest by afternoon. We have one last shot of snow for Thursday and Friday with cooler temperatures and 6 inches to a foot of new snow. After that, we have sunny, warm weather for the holiday weekend through about Tuesday.

Regional Snow Profile (this profile can also be found daily off our home page under avalanche products)

Seasonal Weather History Charts.

Yesterday, Wasatch Powderbird Guides didn’t get out due to weather and today, they’ll be in Cardiff, Days, Silver and American Fork with an avalanche class in Grizzly Gulch. For more info, call 742-2800.

We appreciate any backcountry snow and avalanche conditions you observe. Call (801) 524-5304 or 1-800-662-4140, email [email protected] or 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.

To have this advisory automatically e-mailed to you each day, click HERE. (You must re-sign up this season even if you were on the list last season.)

UDOT also has a highway avalanche control work hotline for Little Cottonwood road, which is updated as needed. 801-975-4838.

The annual report for 2004-05 is now on the web. (Click HERE, 8mb)

I will update this advisory by 7:30 Wednesday morning. Thanks for calling.