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”
December 31, 2007 7:30 am
Good morning, this is Bruce Tremper with the
Special Avalanche Advisory:
A Special Avalanche
Advisory has been issued for the
was a wild day in the mountains with very strong west to northwest winds, heavy
snow and widespread avalanche activity.
Very difficult trail breaking in upside down snow and poor visibility
helped to limit backcountry avalanche incidents. The winds blew as hard as 55 mph, gusting to
80 on the most exposed peaks. 8-18 inches of snow fell yesterday with storm
totals of 2-3 feet over the weekend. The
wind has decreased a little this morning, but it’s still blowing hard from the
northwest 20-40 mph with stronger gusts.
Ridge top temperatures have plummeted to zero. It’s
Ski area control work
reported widespread, sensitive wind slabs at almost all aspects and elevations
and many natural avalanches occurred in the backcountry yesterday within the
new snow. One experienced backcountry
skier backed off the steeper slopes in lower Butler Fork in Big Cottonwood
Canyon and on his way out, triggered an 8 inch deep, 100’ wide, wind slab that
buried the trail 4’ deep (PHOTOS).
I expect that the snow has settled a bit overnight, especially with the colder temperatures, which means that we may not see many natural avalanches today, but there’s still plenty of human-triggered potential on any slope approaching 35 degrees or steeper, especially slopes with recent wind deposits. Since the wind affected nearly all terrain, you will find these wind-deposited slopes from near the valley floor to the tops of the mountains and on all aspects. The slabs are stiff, heavy and thick, so any avalanches you do trigger today could easily be tree-snappers and hard to survive.
Bottom Line for the
is CONSIDERABLE on any slope approaching 35 degrees or steeper, especially slopes
with recent wind deposits. This means
that human triggered avalanches are probable.
There is still a possibility of lingering, deep-slab potential shady
slopes facing northwest, north and northeast, above about 9,500’, where it is
possible to trigger a deep, dangerous slide releasing near the ground.
Be advised, there is a HIGH avalanche danger in the
Ridge top winds will
diminish today but you’ll still need a down coat, mittens and a face mask. Winds should diminish from 30 mph from the
west to around 15 mph and ridge top temperatures should remain in the single
digits and near zero on the highest peaks. There’s still a few lake-effect
squalls lingering this morning but we should have partly cloudy to clear skies
for much of the day.
On New Year’s Day, the temperatures should warm dramatically to near freezing and we will be in a strong high pressure ridge for most of the week. Then it looks like another strong storm for next weekend.
UDOT will conduct avalanche control in Little Cottonwood Canyon this morning and they expect to reopen the road by about 8:30 am.
Today the Wasatch Powderbird Guides will fly in the
For an avalanche education class list, updated 12/22/07, click HERE.
If you want to get this avalanche advisory e-mailed to you daily click HERE.
The UAC has temporary job openings for doing avalanche outreach in more rural areas. Click HERE for info.
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 our classic text advisory click HERE.
If you’re getting out and see anything we should know about please let us know. You can leave 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.
Brett Kobernik will update this advisory by 7:30 on Tuesday morning.