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,
February 15, 2007 7:30 am
Good morning, this is
The Banff
Mountain Film Festival will be held at Kingsbury Hall next Tuesday and Wednesday,
February 20 & 21st.
Tickets are $7.50 per show and available at Kingsbury Hall, Art-Tix, the Salt Lake and Sandy REI stores, and the Outdoor
Recreation Program at the U of U. Shows
start at 7pm each night. (CLICK FOR DETAILS)
Current Conditions:
The winds are blowing
hard from the west and northwest. With
the jet over us, the higher elevation stations are blowing significantly harder
than ones just a couple thousand vertical feet lower. At 11,000’ the winds are blowing 40, gusting
to 60 but most other ride top locations are blowing 20 gusting to 35. Temperatures are cold this morning around 13
on the ridge tops but they will warm up into the 20’s later today with
continued strong winds and light snow showers, which will increase avalanche
danger throughout the day.
Recent Avalanche Activity:
Although snow
avalanche activity has thankfully diminished from the widespread activity on
Sunday and Monday, there are still many slabs hanging in the balance just
waiting for a trigger. Yesterday, a
snowboarder triggered an avalanche that was caught on video near Guradsman’s Pass. He
miraculously escaped despite being strained through trees. Also, a backcountry skier triggered an
avalanche on a ski cut on Box Elder Peak.
It was on a steep, north facing slope around 9800’ and it broke 2 or
more feet deep and 60 feet wide. He
narrowly escaped being caught. PHOTO. Also, someone
collapsed the flat slope at the top of Flanigans,
which is a tree-gladed slope in Silver Fork near
Solitude, and it triggered a 2’ deep avalanche on faceted snow.
Snow and Avalanche Discussion:
Today the main concern will be fresh wind slabs forming from the strong west to
northwest winds. Strong winds combined
with rising temperature will create sensitive wind deposits. They will form mostly along the upper
elevation east to south facing slopes, but they will be cross-loaded onto other
slopes as well. Be sure to avoid all
steep slopes with recent deposits of wind drifted snow. They will look smooth and rounded and often
feel slabby and south hollow.
Also, as you will get tired of us saying, this extremely weak and fragile layer
of depth hoar, buried about two feet deep, will not
gain strength very rapidly. It will
continue to produce avalanches every time new snow or wind blown snow overloads
it and occasionally when someone jumps on it.
These are the kinds of pesky conditions where several people can get
away with a bold line but the next person will trigger a large, potentially
deadly avalanche. All the cagy people I
know are continuing to play it conservative and staying on gentler slopes. Remember that you can trigger avalanches from
a distance, so avoid travel below steep terrain.
FYI, I investigated a huge avalanche that skiers triggered in White Pine Canyon
on Monday. Several slopes avalanched at
once and it took out both their up tracks and descent tracks. They were very lucky. PHOTOS.
Bottom Line for the
The avalanche danger
remain CONSIDERABLE
on any slope steeper than about 35 degrees with recent wind deposits and also a
lingering CONSIDERABLE
danger even on non-wind drifted slopes that face northwest, north, northeast
and east above about 8,500’. Other
slopes will have MODERATE danger. You should continue to stay on gentler
terrain.
Mountain Weather:
Today and Friday we
will have a moist, west to northwest airmass with
strong winds and rising temperature. We
should get about 6 inches today and another few more inches tonight with more
snow accumulating the farther north you go.
Ridge top winds will continue to be strong, around 35, gusting to near
60 from the west and northwest and will continue strong on Friday. Ridge top temperatures will be in the lower
teens this morning and rise to the lower 20’s by afternoon. Total snow accumulation by late Friday could
be around 10 inches in favored areas.
The extended forecast calls for warm and dry this weekend with a storm early in
the week with most of the energy diving south of us, but it should give us a
few inches of snow.
Announcements:
Yesterday, the Wasatch Powderbird Guides flew in American Fork, Silver
Fork and Grizzly. Today, they most
likely be shut down for wind and snow, but if possible, they will be in the
same areas plus
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.
Brete Kobernik will update this advisory by 7:30 on Friday morning, and
thanks for calling.