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

Friday, December 23, 2005 7:30am
Good morning, this is Evelyn Lees with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory. Today is Friday, December 23, 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.

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:
A night of mixed rain and snow has created a wet, soggy mess this morning. Above about 9,000 feet, 6” of damp, 15 to 20 percent density snow has been reported. Below about 8,000’, over an inch of rain has fallen in many locations from Ogden to Provo. Temperatures have cooled to near 30 at 9,500’, but remain above freezing at 7,500’. Winds have shifted from the southwest to the northwest, and are in the 10 to 20 mph range, with gusts in the 30’s. Across the higher peaks, hourly averages are closer to 30 mph with gusts to 60.

Avalanche Conditions:
The snowpack is complex, with wet snow avalanche problems at the mid and low elevations and winter like conditions at the higher elevations.

Overnight rain has soaked the snow pack below about 8000’ (9000’ Ogden mountains) and wet snow sluffs will be easy to trigger on steep slopes. Sinking in to slushy snow and roller balls are signs you need to stay off of steep slopes. Avoid traveling in terrain traps such gullies and below steep road cuts where even a small avalanche can pile the wet snow up deeply. As skies clear and become sunny today, the danger of wet snow sluffs and slabs will rise on and below steep sunny slopes at all elevations. Both human triggered and natural wet sluffs and wet slabs will be possible, so avoid travel on and below steep sunny slopes.

At the more wintry upper elevations, the combination of dense snow and strong winds will have created stubborn drifts of wind blown snow, especially along the ridgelines. These drifts will be tricky, and let you get out onto a slope before breaking above you. Once a slide starts moving, it has the potential to trigger a deeper slide on upper elevation, northerly facing slopes. Cornices are softening, and may break back further back than expected.

Bottom Line: The danger of wet slides and sluffs is MODERATE this morning on steep slopes below about 8,500’. The avalanche danger will rise to CONSIDERABLE on steep, sunny slopes of all elevations once skies clear. Both natural and human triggered wet sluffs and slabs will be possible. The avalanche danger is MODERATE on steep slopes with recent drifts of wind blown snow.

Mountain Weather:
Last night’s storm is rapidly exiting the area this morning, with slightly cooler air filtering in behind it. This will produce a few additional snow showers this morning before the skies clear. The northwesterly ridgetop winds will be in the 10 to 20 mph range, with stronger speeds across the highest peaks this morning. Temperatures today will be in the upper 30’s at 8,000’ and the mid 20’s at 10,000’. A high pressure ridge will control the weather through the weekend, bringing clear skies and unseasonably warm temperatures. A cooler storm should affect the area around Monday.

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

Click here for Seasonal Weather History Charts.

Yesterday, Wasatch Powderbird Guides did not fly, and today, weather permitting, they will fly in Mineral, Cardiff, Days, Silver, Grizzly and American Fork. 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 Saturday morning. Thanks for calling.