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
Sunday,
April 13, 2008 7:30 am
Good morning, this is
Special Announcement:
Snow storms last week
added up to 2 feet of cold dry snow which has been very susceptible to rapid
warming and produced natural avalanche activity on Saturday. With warmer temperatures today and Monday
natural avalanche activity is expected to continue and could produce quite
large avalanches. This will be most
pronounced in the
Current Conditions:
Today is the last
regularly scheduled avalanche advisory for this season. We will continue to do updates as weather and
snow conditions warrant through April. Thank you very much for all the backcountry observations we
received this year and keep them coming if you’re still getting out.
Temperatures cooled
down overnight enough to refreeze the snow surface but they didn’t get as cold
as Friday night. Most mountain locations
are in the mid to upper 20s but there are a notable amount of places hanging
right around freezing. Wind speeds
slowed yesterday afternoon and are averaging less then 10 mph from the
northwest only gusting into the 20s along the highest peaks. A fair number of people got out on Saturday to
milk the last of the cold snow which can still be found on the high due north
aspects and most reported crusts on all other aspects.
Snow and Avalanche Discussion:
Not surprisingly most
people who stayed out later in the day reported wet avalanche activity which
was both natural and human triggered. A
natural wet slab released 200 feet wide running a few hundred vertical and
stopping just short of a house on a south facing slope at around 8300 feet in
elevation in Big Cottonwood. A couple of
larger naturals released in Little Cottonwood not quite hitting the road. There were also a number of human triggered
small wet loose snow avalanches on Saturday.
A few cornices are starting to let loose as well. Skiers in upper Porter Fork reported a few
collapses of the snow pack and snow safety at
Again today the main
concern revolves around heating of the upper portion of the snowpack. Let’s look at the pluses and minuses. On the plus side, we’ve had a couple of days
of gradual warming with successive refreezes.
With every refreeze the temperatures the next day need to penetrate the
snow more to loosen it up. On the minus
side, today’s highs are expected to be warmer then yesterday’s and likewise for
Monday. Will this override the past few
melt freeze cycles loosening the snow to the point of failure? If you know the answer to this please call the
boys at Little Cottonwood UDOT and drop me a line also, we’d like to know your
formula. You can be pretty sure you won’t
stumble across me having lunch this afternoon at the bottom of any steep slide
paths. I’ll be joining some of you snow
safety personnel at your Bar-B-Q watching from a safe distance.
Not many cornices have
come loose due to warming yet but one of our up and coming backcountry
observers did note a few on his tour through Bells on Saturday. We need to give these things due respect
during this period of warming. They tend
to break off quite large and often farther back then expected. They can also entrain enough snow or trigger
an avalanche below which if the cornice fall doesn’t do you in, the avalanche
may.
Bottom Line for the
The avalanche danger
starts out generally LOW this morning with
only a few isolated places where you may trigger a dry slab on the upper
elevation north aspects. The avalanche
danger will rise to CONSIDERABLE with daytime heating. Large natural avalanches could release on
east, south and west facing slopes.
Mountain Weather:
Clear skies with 8000 foot
temperatures near 50 or better and in the mid to upper 40s along the upper
ridges are in store. Westerly winds
should be fairly light along the ridges.
Temperatures will only drop into the upper 20s again tonight and a
number of places may not get below freezing.
Monday is again mostly clear and warmer yet with increasing southwest
winds. A cold front is scheduled for
Tuesday which may produce 2 to 4 inches of snow.
Announcements
The Wasatch Powderbird
Guides were in Mineral and
If you want to
get this avalanche advisory e-mailed to you daily click HERE.
UDOT highway avalanche control work info can be
found by calling (801) 975-4838.
Our statewide tollfree line is 1-888-999-4019 (early morning, option 8).
Watch video tututorials and fieldwork from UAC staff at our YouTube
channel.
The UAC depends
on contributions from users like you to support our work. To find out
more about how you can support our efforts to continue providing the avalanche
forecasting and education that you expect please visit our Friends page.
If you see any avalanches or interesting snow conditions, 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.
We’ll do intermittent updates as conditions warrant through April.