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
AVALANCHE ADVISORY
Saturday,
December 30, 2006 7:30 am
Good morning, this is Evelyn Lees with
the
Current Conditions:
Up in the mountains, skies
are mostly clear this morning, and temperatures have warmed overnight into the
low to mid twenties at many locations. The
winds have shifted to a more northerly direction and decreased to less than 15
mph, except for pesky speeds of up to 20 mph, with gusts to 30 across the
highest terrain. Snow surface conditions
include variable wind sculpted, wind drifted, wind blasted, and breakable
crusts in open bowls and along the ridgelines. But the good news is that quality turns do exist
in shallow powder on your favorite wind sheltered, mid elevation, shady slope.
Snowpack and Avalanche Conditions:
Yesterday, people had varying experiences with the widespread, poorly
bonded wind drifts (slabs) - some were stubborn or just plain non reactive, while
others cracked out up to a couple meters wide. But even those that cracked were very shallow
generally less than 6 deep. There was also
evidence of a small natural cycle of these wind slabs from sometime
Thursday. Today, continue to avoid steep, wind drifted slopes as it may still be
possible to trigger one of these hard wind drifts. Watch for drifts at both mid elevation
breakovers as well as along the ridgelines.
Though they are generally very shallow, triggering one of these hard
drifts could knock you off your feet and send you for a ride over a cliff or
into trees on steep slopes.
Also keep in mind that on most aspects there
are several buried layers of weak facets. Yesterday, one Ogden area resort had an
explosive triggered slide in a tight, east facing chute that was 3' deep x 100'
wide, stepping down to the ground on facets.
Also half a dozen slides have been
triggered in the backcountry on the uppermost facet layer over the past 10 days
(click
for avalanche list). To trigger one of these faceted layers (Click for a snowpit from the 29th), youd need the infrequent combination of wind loading
adding significant weight and a denser, stiff slab to a slope where the faceted
weak layer exists.
Bottom Line for the
The avalanche danger
is MODERATE on any slope steeper than about 35
degrees with recent deposits of wind drifted snow. Be especially cautious on slopes facing west
through north through east, where slides could break deeper on a faceted weak
layer. However, these areas are
isolated, and most backcountry terrain has a LOW danger.
Mountain Weather:
A high pressure ridge building
in across the
Announcements:
Yesterday, Wasatch Powderbird Guides flew in Cardiff and American Fork,
and today will fly in Silver, Days, Cardiff, Mineral, Grizzly, White Pine,
American Fork, Cascade and the Sessions.
The
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.
Drew Hardesty will update this advisory by 7:30 on Sunday morning, and
thanks for calling.