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
Current Conditions: The entrenched high pressure system will bring mostly sunny skies,
calming winds from the northwest and warmer temperatures in the mountains
today. Currently under partly cloudy
skies, the CSI weather station on
Avalanche Conditions: It
was another very active day in the
Solar
warming will quickly heat up already moist snow on sunny slopes at all
elevations, and crusts that formed overnight will quickly soften. Wet avalanches will be likely on many steep
slopes in the middle of the day as the fresh surface snow is warmed and becomes
saturated. Watch for roller balling and
other wet activity on similar slopes, and leave or reevaluate if the snow on
the slope you’re on gets sloppy. Snow
dropping off trees, cornice falls and humans are all likely triggers of wet
avalanches today. Remember that wet snow
conditions can deteriorate rapidly during the day, often making the exit from
upper elevations in the backcountry more dangerous than the entrance.
Stiff
wind slabs on south facing slopes were certainly not well bonded to the crusty
old snow surface, with the slab failing on isolation in test pits. The weakness at the old/new snow interface that
I found yesterday was a layer of graupel capping a solid sun-crust. These graupel layers have a tendency to
enhance facet growth, especially when they fall at the interface between warm
old snow and colder new, and the weak layer currently developing is a notorious
persistent weak layer. Light snow fell
with little or no wind early in the weekend, and in some areas it may have
preserved weak layers that formed on or near the snow surface during last week’s
high pressure. (snow photos)
Today,
warming will soften wind slabs formed on sunny slopes during the weekend storm…This
may make them more sensitive to human triggering. Sun softened wind slabs might pick up steam
and moist surface snow and could run pretty far today on existing smoothed in
and crusted bed surfaces, especially on big slopes.
.
Bottom Line: There’s
generally a MODERATE
danger in the backcountry, and triggered persistent slab and wet point-release avalanches are possible slopes steeper
than about 35 degrees. Solar
warming today is likely to cause a CONSIDERABLE
danger of both wet sluffs and slab avalanches on steep sunny slopes with
saturated surface snow. Use good snow
assessment and safe travel techniques to minimize your risks and avoid and stay
out from under steep sun-warmed slopes with saturated snow.
Mountain Weather:
A high pressure system will rule
the weather pattern for the rest of the work week, with the next storm coming
over the weekend. Light winds today will
again allow solar warming to heat concave south facing slopes, like solar ovens,
and mountain temperatures will be a bit warmer. Daytime temperatures will continue to rise in
the next couple days. A storm is probable late Saturday, lasting
into Sunday, and another looks to be hot on its heels for next Tuesday.
Upcoming avalanche class: February
29th-March 1st, Avalanche Basics,
Check out the images page for photos of some of
this season’s avalanches.
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.
