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,
December 13, 2007 7:30 am
Good morning, this is
I will give a free avalanche awareness talk tonight
for the Wasatch Mountain Club but the public is welcome. It will be at 7:00 pm at the
There will be a benefit for our partners, the
Friends of the
Alta Community Enrichment will be
sponsoring a free women's avalanche beacon clinic today, December 13th, from 9
am until around noon. Meet inside the Albion Grill at Alta's Ski Lift's
upper lot at 9am. Skies, snowshoes or just boots OK. Extra beacons
available. For more information call 742-9712 OR EMAIL [email protected].
Current Conditions:
Temperatures
are about 5 degrees warmer this morning than yesterday morning with ridgetop
temperatures 5-10 degrees. Ridge top
winds are reasonable around 10 mph from the northwest and around 15 mph on the
most exposed peaks. You can expect
increasing clouds through the day with light snow showers tonight.
Snow surface conditions are the usual mixed bag after it has not snowed in a
few days. There is sun crusted snow on
the south facing slopes, some wind damage within 100 feet of the ridgetops from
northeast winds a couple days ago. But
the slopes that face the north half of the compass are still quite
delightful. The biggest complaint, of
course, is the shallow snowpack on all slopes except upper elevation north
facing, where you hit many rocks.
Avalanche Discussion:
We did not hear about
any avalanche activity yesterday from the backcountry.
The main problem is our old layer of weak, faceted snow left over from the
November drought, which existed only on the slopes that face the north half of
the compass above about 9,500’. Everything
else was bare ground, so when the snowstorms finally started a couple weeks ago,
the new snow stuck well to everything except the aforementioned high north
facing slopes, where there was widespread natural and human triggered
avalanches last weekend and the weekend before.
Even though most of these slopes have slid already, there are still a few
lingering slopes that you can still trigger.
For instance, one very experienced skier triggered one a couple days ago
in Wilson Glade, which is a northeast facing slope near Gobbler’s Knob between
30 and 35 degrees in steepness (Link). I suspect there are other slopes like this that
are still hanging in the balance. A pattern we often see is that the slopes
35-45 degrees slide during the storm, but afterwards, a few slopes slightly
less than 35 degrees still linger waiting for a trigger. Any avalanches triggered on these slopes will
be large—around 3 feet deep and quite wide.
With the recent wind and some snow, it’s getting hard to tell which slopes slid
during the last storm, so you have to do some creative research and poking
around to sort out the safe slopes from the unsafe ones.
Also, strong northeast
winds a couple days ago created some wind slabs along the upper elevation
ridges that may still be lingering. So
as usual, you should avoid any steep slopes with recent wind deposits.
Bottom Line:
The
avalanche danger is MODERATE on upper
elevation northwest, north and northeasterly facing slopes steeper than about
33 degrees, above about 9,000’ in the
Throughout
all the range, there is also a MODERATE avalanche
danger on any steep slope with recent wind drifts, which you will find mostly
along the upper elevation ridges.
Mountain Weather:
We will have
increasing clouds today in advance of a weak cold front tonight, which should
bring us 2-5 inches of snow. It will be
just enough to freshen things up a little, but
probably not enough to increase the avalanche danger very much. Ridge top winds today will be west to
northwest 15 mph and temperatures should be near 10 degrees. Friday morning, ridge top temperatures will
drop to just above zero and ridge top winds should not rise
much above 15 mph.
We will have another, weaker, system by this weekend and the longer ranger
models indicate a stronger system in about another week.
(Click HERE where you
can get another look at the weather on our revamped weather page. This page, which we update
every day around noon.)
Announcements:
For an avalanche education class list, 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.