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
“keeping you on top”
February 21, 2007 7:30 am
Good morning, this is Evelyn Lees with the
It is a warm, blustery morning in the mountains. 10,000’ temperatures are in the mid 20’s, 15 to 20 degrees warmer than yesterday morning. The southwesterly winds have been cranking in the 20 to 25 mph range with gusts to 45, with the windiest locations gusting in the 50’s to 60. Turning and riding conditions are excellent on shady, wind sheltered low angle slopes, and the sunny slopes have crusts that will soften with daytime heating.
Snow and Avalanche Discussion:
Yesterday was another
day full of close calls in the backcountry, with four dangerous human triggered
avalanches and one natural. On east
facing High Ivory in Cardiff Fork, the third skier on the slope triggered 300’
wide hard slab, on southeast facing Raymond shoulder a skier triggered a 1-2’
deep slide, a hard slab was triggered out of bounds near the top of Millicent
lift on a northwest facing slope, and an intentional cornice drop in West
Monitor triggered small slide that then stepped down, 5-8' deep x 150' wide. Mid day, a NATURAL ran on Gobblers, 700' off
top, 150' wide, running 800 vertical into a gully. In addition, there were both
natural and human triggered wet loose slides on steep sunny slopes and numerous
reports of collapses. With good visibility, there were reports of substantial
natural activity that occurred Monday from
Persistent, unrelenting…the weak layer of sugary facets and surface hoar is here to stay. The continuing string of dangerous human triggered slides on this deep faceted weak layer proves there are still many places a person can trigger a slide, and that the weak layer remains sensitive for days after each storm or wind loading event. The pattern is complicated and tricky, and no one’s got x-ray vision to look into the snowpack and figure out which slope may slide, and which won’t. The best bet is to go for the great turning and riding conditions on low angle slopes. Any shallow slide triggered has the potential to step down to these faceted weak layers, for a deeper, more dangerous slide.
The strong southwesterly winds will create new, sensitive drifts of wind blown snow today, most widespread along the ridgelines and on slopes with an easterly component. But watch for and avoid drifts cross loaded onto other aspects and around sub ridges and breakovers well off the ridgelines due to the high wind speeds. With another day of warm temperatures and lots of sun, expect easily triggered and natural wet loose sluffs and slabs, and increased sensitivity of even the dry cold snow slabs.
Bottom Line for the
Back off the steep stuff – if the close calls continue, someone else is going to get killed or hurt. The avalanche danger remains CONSIDERABLE on slopes steeper than about 35 degrees facing northwest through northeast through southeast, where dangerous avalanches 1 to 3 feet deep can be triggered by people. The danger is also CONSIDERABLE on any steep slope with recent drifts of wind blown snow. Natural avalanches are possible on steep wind drifted slopes and steep sunny slopes.
Today’s weather will
continue to add to the avalanche problems.
The southwesterly winds will remain in the 15 to 25 mph range, with
gusts to 40 along most ridges. The
highest terrain will have gusts into the 50’s.
Skies will be clear and sunny, and temperatures warm, in the upper 30’s
at 8,000’ and the mid 20’s at 10,000’. On
Thursday, the winds will strengthen substantially ahead of an approaching cold front,
which should reach northern
Tonight is the last night of the Banff Mountain Film Festival at Kingsbury Hall. Tickets are $7.50 and available at Kingsbury Hall, Art-Tix, the Salt Lake and Sandy REI stores, and the Outdoor Recreation Program at the U of U. The show starts at 7pm. (CLICK FOR DETAILS)
Yesterday, the Wasatch Powderbird Guides flew in
Listen to the
advisory. Try our new streaming audio or
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 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 all the great snowpack and avalanche observations we’ve been getting, so keep leaving us messages 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, and thanks for calling.