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

Wednesday, December 13, 2006 7:30 am
Good morning, this is Evelyn Lees with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory. Today is Wednesday, December 13, 2006 and it’s 7:30 in the morning.

UDOT plans to conduct artillery control work in Little Cottonwood Canyon this morning, beginning at 10 am. Please stay clear of the avalanche paths on the north side of the canyon from Tanners to White Pine until after 10:30 am. For updates, call 801-975-4383.

Current Conditions:

Skies are mostly cloudy this morning, and temperatures have warmed into the mid 20’s at 9,000’. 24 hour snow totals south of I-80 are in the 1 to 3” range. Portions of the Ogden and Logan area mountains have received more, with up to .7” of water. The westerly winds have increased this morning into the 10 to 15 mph range, with gusts in the 20’s. The highest peaks are averaging 25 to 35 mph, with gusts to 45.

Snowpack and Avalanche Conditions:

Throughout the range, all reports were of stable snow yesterday. With effort, you could trigger a small sluff on a steep slope, but the snow still refused to act as a cohesive slab, despite weakness within the new snow. Today, with another few inches of warm, dense snow in the forecast and slightly faster wind speeds, sensitive wind drifts may develop in upper elevation terrain, especially along the ridgelines. Watch for cracking of the snow around your boards, and use slope cuts on test slopes and cornice kicking to test if a slab is developing. If you missed these links yesterday, here are some great demos of the shovel tilt test, which also works well to reveal the weaknesses in the upper pack. (PHOTO) (Quicktime video, 5.3mb),

The creepy part of backcountry travel these days is due to all the layers of sugary, faceted snow deeper in the pack, most widespread outside the deeper snowpack of upper Little and Big Cottonwood Canyons. So far, the small, incremental loads of snow are allowing these facets to adjust to the added weight. But at some point, the facets on an individual slope will become overloaded. There is potential for one of these deeper slides to occur in the Ogden area mountains today if the forecast snow and water amounts verify. New drifts of wind blown snow will also be more widespread, deeper and sensitive in the mountains north of I-80.

Bottom Line:

Salt Lake, Park City and Provo mountains: the avalanche danger is MODERATE on upper elevation slopes steeper than about 35 degrees, especially with recent deposits of wind drifted snow. The danger may increase and become more widespread later today and tonight with additional snow and wind. Out of wind affected terrain and on slopes less steep than 35 degrees, the danger is LOW. Ogden area mountains: the avalanche danger is MODERATE on all slopes steeper than 35 degrees, and may increase to CONSIDERABLE during the next 24 hours in areas that receive more snow and wind today.

Mountain Weather:

A moist westerly flow will be over northern Utah through Thursday. Another round of light snow fall should begin later this morning, with the mountains south of I-80 receiving 1-3” and the mountains north of I-80 3-6”. Winds will remain from a westerly direction, in the 15 to 20 mph range at 10,000’, with gusts in the 30’s. The highest peaks will have stronger speeds of 25 to 35 mph, and gusts to 60 mph. Temperatures will be in the mid 30’s at 8,000’ and the upper 20’s at 10,000’. A colder storm system will move into the Great Basin on Friday.

Announcements:

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)

For a list of avalanche classes, click HERE

For our classic text advisory click HERE.

To sign up for automated e-mails of our graphical advisory click HERE

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.

Bruce Tremper will update this advisory by 7:30 on Thursday morning.