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
Thursday,
March 01, 2007 7:30 am
Good morning, this is Bruce Tremper with
the
Current Conditions:
Our
apologies. The Internet-based advisory is late this
morning because of computer network problems at the National Weather Service
About 4 inches of new snow fell overnight and you will want your down coat,
mittens and face mask today because the ridge top temperatures are between zero
and 5 degrees with a stiff west-northwest wind blowing 20 gusting to 40 along
most of the ridge tops and 40 gusting to 60 on the most exposed peaks. We’re expecting snow for most of today,
tonight and Friday morning.
Snow and Avalanche Discussion:
Yesterday Evelyn
suggested that everyone do some sightseeing to marvel at some of the huge,
natural avalanches that occurred Tuesday.
Sure enough, many folks had a memorable day and they e-mailed us dozens
of spectacular photos last night from throughout northern
When people trigger these large avalanches, they typically do so where the slab
is thinner, such as mid slope near rocks, or they drop a big cornice on the
slope. Once it starts ripping, it can
propagate into deep, hard layers making very large avalanches. The problem exists mostly on slopes that face
the north or east quadrants of the compass.
Once again, these big mommas may be hard to trigger but if you do, it’s
definitely the nuclear option.
Also, yesterday there was a remotely-triggered avalanche in American Fork when the
WPG helicopter set down on a ridge top landing zone
around 9,500’. It broke out on an
adjacent, steep, north facing slope they never ski and it broke 2-3 feet deep
and 200 feet wide into faceted snow.
Probably more
importantly today, we have new snow with strong wind, which will certainly make
sensitive wind slab avalanches on any steep slope with recent wind drifts. Some of these new snow avalanches have the
potential to step down creating larger and more dangerous avalanches especially
on north through east facing slopes.
Bottom Line for the
Today we will have a CONSIDERABLE
avalanche danger on any slope approaching 35 degrees or steeper with recent
deposits of wind blown snow. There is
also a lingering CONSIDERABLE danger on slopes 35
degrees or steeper, facing northwest, north, northeast, east and southeast above
about 8,000’. Considerable danger means
human triggered slides are probable. 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. Today is another good day for a ski resort. High marking is not recommended. The avalanche danger may rise to HIGH
tonight and on Friday.
Mountain Weather:
The mountains should
continue to get snow throughout the day with another 4-8 inches, probably
intensifying by mid day or afternoon.
Ridge top winds will continue to blow 25 from the west and northwest
with gusts to 40. On the highest, most
exposed peaks, winds will blow 35 gusting to 55. Ridge top temperatures will be chilly, around
5 degrees. Snow should end later on
Friday but the winds will pick up and blow harder.
The extended forecast calls for a warm and sunny weekend with the chance for
another storm on about Wednesday.
Announcements:
The Wasatch Powderbird Guides flew yesterday in
Listen to the
advisory. Try our new streaming audio or
podcasts
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.
Evelyn Lees will update this advisory by 7:30 on Friday morning, and
thanks for calling.