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

Friday, March 02, 2007 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 Friday, March 02, 2007 and it’s 7:30 in the morning.

Avalanche Warning: An Avalanche Warning has been issued for the Wasatch and Western Uinta mountains of northern Utah. Heavy snow and strong winds have created a HIGH avalanche danger, with both natural and human triggered avalanches likely. An elevated avalanche danger will persist through the weekend.

Special Announcements: UDOT will conduct control work above the highway in Little Cottonwood Canyon today. The canyon road should open around 8 am, once control work is complete. UDOT in will conduct control work above the highway in Provo Canyon around mid day, with intermittent road closures. Ice climbing in Provo Canyon is closed until control work is complete.

Current Conditions:

One last storm is capping off a very active 3 weeks. Waves of heavy snowfall yesterday and last night have snow totals pushing 20” in many areas of the Salt Lake, Ogden, Park City and Provo mountains. The northwesterly winds have been averaging 15 to 25 mph at many stations, with gusts in the 30’s and 40’s. Across the highest peaks, hourly averages have been in the 40’s and gusts in the 60’s. With temperatures in the single digits, it’s going to be another viciously cold day until the winds die down.

Snow and Avalanche Discussion:

Yesterday’s reports from the backcountry were of easily triggered sluffs and one to two foot deep soft slabs up to 100’ wide in wind affected terrain and along ridgelines. Cornices were very sensitive, breaking far back onto the ridges. With the poor visibility, strong winds and a rotten snow pack, no one was sticking their necks out.

Today, both natural and human triggered new snow slides will be likely on steep slopes with recent drifts of wind blown snow. I suspect a new snow natural avalanche cycle has and is occurring on steep, heavily wind drifted slopes, so avoid travel beneath steep slopes. Today, it will be easy for people to trigger the new wind drifts, which will be both along and well off the ridgelines. Cornices are very sensitive, and will break back much further than expected, onto the flat ridgelines. Any avalanche triggered in the new snow has the potential to step down, taking out several storms worth of snow or even to the ground, creating a deep, dangerous slide.

With another load of snow, once again it will be possible for both natural and human triggered slides to occur on the deeply buried facets near the ground. These deep, dangerous slides will be more likely in the shallower snow pack areas outside of the upper Cottonwoods, on slopes facing northwest through northeast through southeast, and can be triggered remotely from a distance. Any slide breaking near the ground will be unsurvivable. Lower elevations have their share of this weak basal snow, so avoid steep slopes at the mid and low elevations, too.

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

Today there is a HIGH avalanche danger on any slope approaching 35 degrees or steeper with recent deposits of dense, wind blown snow, especially slopes facing northwest, north, northeast, east and southeast above about 8,000’. High danger means both human triggered and natural avalanches are likely. Both new snow slides and deep, unsurvivable slides breaking to the ground can be triggered by people. People without excellent avalanche skills should avoid backcountry travel today.

Mountain Weather:

A cold front is working its way south across the area, producing intense snow and strong winds. An additional 5 to 10” of snow is possible today. As the front passes, the snow will turn showery and gradually taper off midday. The strong, northwesterly high elevation winds will also decrease this afternoon. Temperatures will be frigid, in the teens at 8,000’ and the low single digits at 10,000’, putting the wind chill at about -15. The weekend forecast calls for clearing skies and temperatures rapidly warming to near freezing at 10,000’ by Sunday.

Announcements:

The Wasatch Powderbird Guides did not fly yesterday and will not fly again today due to weather. With questions regarding their areas of operation call 742-2800.

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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.

Brett Kobernik will update this advisory by 7:30 on Saturday morning, and thanks for calling.