The Utah Avalanche Center Home page is: http://www.avalanche.org/~uac/
(click on) Utah Avalanche Center in Logan for our home page
Logan
Hello and good morning, this is Toby Weed of the
We are issuing an Avalanche Warning for
the mountains of
Current
Conditions:
A
powerful storm with heavy snowfall and strong south and southwesterly winds will
make travel quite dangerous in the backcountry today, and you should avoid
avalanche terrain. While nice powder could be found in many areas this weekend,
we’ve received reports of numerous human triggered avalanches and close
calls. Might be a good idea to hit
the lifts or at least stay in mellower (lower angled) terrain.
Avalanche
Conditions:
Numerous reports of a very active day in the Utah
backcountry are filtering into the Utah Avalanche Center this morning, with
several triggered avalanches, some stepping into old snow and a handful of
people taking unintended rides. Locally, I have reports of a couple spooky human
triggered avalanches from this weekend.
Just as we thought, recently deposited stiff wind slabs are clearly still
sensitive to human weight. We’ve
observed evidence of numerous natural and a few triggered wind slab avalanches
in the backcountry over the last week. I’ve posted pictures of a few on the images page.
The reports and observations are
mainly from lower and middle elevations, and there have been recent local
avalanches on a wide variety of slopes facing most directions and at all
elevations. On Friday we ventured
into a lower elevation area in the Southern Wellsville Range where widespread
natural avalanching occurred overnight, (photos). A skier triggered an avalanche on a
drifted north facing slope at around 6300’ in the foothills south of the mouth
of Green Canyon on Friday that was reported to be around a foot deep and a
couple hundred feet wide. The
avalanche ran around a thousand vertical feet before stopping within a stones
throw of the road to the trailhead.
And, yesterday a skier fell at around 8300’, triggering a 3’ deep slab
avalanche in “the Gut” of the popular east facing bowls in the Garden City
Canyon/Swan Peak Area. The lucky
skier escaped injury after a short ride.
The winds picked up from the south again overnight
and are gusting close to 50 mph this morning. Freshly built wind slabs will surely be
an issue again today, and heavy snowfall accompanying strong winds may well lead
to extensive loading over large areas often quite a ways off ridge lines. The incoming powder will obscure many
drifts, and last week strong southwest winds caused extensive drifting and built
hard and soft slabs on numerous steep slopes across the region. Now these are
buried and hidden. The biggest recent wind deposits are at upper
elevations, near ridge tops, and on slopes facing the eastern half of the
compass, but there are significant stiff drifts at all elevations and on slopes
facing all directions. Watch for cross-loaded slopes where drifts piled up in
and around terrain features like gullies, cliff bands, and
sub-ridges
Wind-drifted snow overloaded some steep slopes with
existing persistent weak layers.
There is potential for some avalanches to step down to one of several
lingering weak layers formed on the snow surface before last week. These now buried weaknesses consist of
thin sugary or faceted layers located under brittle sun crusts on some slopes
and including frost crystals or surface hoar on others. In areas with a shallow overall snowpack
some avalanches could step all the way down to sugary depth hoar near the
ground.
Bottom
Line:
There is a HIGH danger in the
backcountry today, and natural and triggered avalanches are likely on a variety
of steep slopes and at all elevations during periods of strong wind and heavy
snowfall. In some areas, wind-drifted snow
overloaded slopes with existing persistent weak layers, and the danger will remain CONSIDERABLE for a while
even after the storm departs. Avoid and stay well out from under steep
slopes and obvious or historic avalanche paths…
Mountain
Weather:
The National Weather Service has issued a Winter
Storm Warning for the mountains around
Check out photos of avalanches in
the Logan Area on our images
page.
Go to the
Avalanche
Encyclopedia if you have any questions about
terms I use in the advisory.
I'm very interested to know what
you're seeing out there. Please e-mail observations to me at
[email protected] or leave me a message at 755-3638,
especially if you see or trigger an avalanche in the backcountry. We keep all
observations confidential.
This advisory will expire in 24
hours from the posting time.
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.
