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
AVALANCHE ADVISORY
Wednesday,
April 12, 2006 7:30 am
Good morning, this is Evelyn Lees with
the
Current Conditions:
A multi-day warm up has begun,
with temperatures this morning 5 to 10 degrees warmer than yesterday. Temperatures did dip below freezing above
about 10,000’, but readings in the upper 30’s to low 40’s are common at the mid
and lower elevations. The southwesterly
winds have increased into the 20 to 30 mph range, with gusts in the 40’s and 50’s
along the exposed ridge lines.
Recent Avalanche Activity & Snowpack Discussion:
Yesterday, there were
reports of a few wet loose sluffs and 3 shallow small slabs involving the new
snow only. Two new glide cracks were
observed – one on a lower break over in Silver Fork and the other in west
facing Stairs Gulch, at about 9,000'.
There will be an increasing
avalanche danger today through Friday due to the warming temperatures. So the focus is on that lengthy list of heat
related avalanche problems. The
overnight refreeze
is shallow, and the snow will quickly soften, with the low and mid elevation rapidly
becoming punchy and unsupportable. Both wet
loose sluffs and shallow slabs will be more common today. While expected on steep sunny slopes, the shady
slopes will also get active as the newest snow heats up today. Once you trigger a sluff or slab, there is
the potential for it to gouge down into the older, wet snow, resulting in a larger
slide with a deeper debris pile. Carefully
avoid terrain traps such as gullies where even a small slide can bury you.
The large ridgeline cornices will
continue to weaken, often breaking back further than expected, or could fail
naturally, triggering a slide. Glide avalanches
and wet slab avalanches are tricky, and could take place over the next few days. Glide avalanches occur when melt water
lubricates the ground, and the entire snowpack moves and fails as a unit. They come down randomly, not necessarily with
the heat of the day. Wet slabs occur
when the snow pack heats and water weakens or pools on a mid pack layer, often above
a crust or in at the interface between two layers of different crystal types. Shallow surface refreezes can often hide a
wet weak layer beneath.
Best procedure for the next
few days is to travel early in the day, and go home once the snow heats up, or
carefully stay on cooler aspects and lower angle slopes. Avoid travel beneath glide cracks and large
cornices at any time, day or night.
Bottom Line:
The avalanche danger is MODERATE today, and
may increase to CONSIDERABLE with day time
heating. Wet loose sluffs and shallow
wet slabs will be easily triggered by people on steep slopes of all aspects,
including northerly facing slopes and at the mid and low elevations. With a prolonged warming trend forecast, the
avalanche danger will increase through Friday, with wet slabs and glide avalanches
a concern.
Mountain Weather:
Skies will be partly cloudy
this morning, with a few rain and snow showers possible, quickly changing to a mostly
sunny afternoon. High temperatures will
be near 50 at 8,000’ and in the upper 30’s at 10,000’. The southwesterly
winds will remain in the 20 to 30 mph range, with strong gusts across the
ridgelines. Dry, warm and breezy through
Friday, with a mild Pacific storm due to arrive Friday night. Warm and dry again on Sunday, with a
stronger, colder storm possible early next week.
Announcements:
The second annual “Beacon and Eggs” contests are
in full swing, with BIG prizes to the winners.
The next big event is next Saturday at Snowbird. For more information, go to http://www.snowbird.com/events/events/beaconandeggs.html
Early birds and snow
geeks can catch our 6AM report at 364-1591.
Click here to check out our new online avalanche
encyclopedia.
Click HERE for a text only version of the avalanche advisory.
To have this advisory automatically e-mailed to
you each day, click HERE.
UDOT also has a highway avalanche
control work hotline for Big Cottonwood, Little Cottonwood, and
The Wasatch Powderbird Guides did not get out yesterday and are unlikely to fly
today. If they do, they will be in
Special announcement:
The
Please report any backcountry snow and avalanche conditions. Call (801) 524-5304 or 1-800-662-4140, email [email protected] or 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.