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
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you on top”
AVALANCHE ADVISORY
Sunday,
February 24, 2008 7:30 am
Good morning, this is Drew Hardesty with
the
Current Conditions:
It already seems like
we’ve closed the chapter on yesterday’s book.
The southerly winds, ahead of what looks to be a complex, impressive
system, picked up overnight and have been blowing 30-45mph with gusts to near
80. Ahead of the trof, temperatures
continue their steady march into the upper twenties and mid 30’s and we can
expect an initial rain/snow line of about 7000’ with at times heavy snowfall
favoring the Ogden, Park City and Provo mountains. It all shakes out to be a warm, wet, windy
event. Yesterday’s face shots and
over-the-hood riding is already a distant memory.
Snow and Avalanche Discussion:
Yesterday’s activity
centered around continued sluffing and human triggered
soft slabs of less than a foot in steep upper elevation terrain. At least one skier took
a ride and bumped through some rocky terrain after triggering a pocket in
steeper terrain off the Cardiac ridge in upper Cardiff Fork of BCC. My own ski/slope cut produced debris that ran
over 1000’, but that was only the first of a series of increasingly unfortunate
events. More on that here.
Others, on the steep sunny exits,
triggered wet sluffs “with every turn” as they descended back to their
cars. 3rd hand
info had a couple people forced into ‘unintentional hip-checks’ with the
excitement. Preserved cold, low
density stellars on a multitude of hard, underlying bed surfaces were to blame
for the activity, and are likely to be overwhelmed again by today’s onslaught
of wind and snow. An outlier report of a
skier triggered hard slab came in from southeast facing McDonald Draw. It was reported to be 8-12” deep and 100’
wide, triggered in the high terrain there at 9500’, and the skier avoided
capture.
It’s not rocket
science. The strong southerly winds will
have already whipped up some sensitive new wind drifts in and below the
standard starting zones in lee terrain.
The northerly aspects will be more prone, but crossloading and eddying
will put all deceleration zones at risk in complex terrain. I do not expect the new snow to bond very well
to the old bed surface, but with potentially high snowfall rates, and storm
totals approaching 16-20”, it may all be academic. Some avalanches are likely to step down about
a foot or so to the older bed surfaces on the preserved stellars. Low elevation wet avalanches will be likely
on the shadier aspects with a 7000’ rain/snow line and roof-alanches are a
distinct possibility.
Bottom Line for the
It’s going to be a
tricky and complex bottom line today. Due
to the strong winds, Pockets of CONSIDERABLE danger exists in steep wind loaded terrain this morning in the
Mountain Weather:
A powerful trough
packing strong winds and dynamics suitable for high water amounts for the
Wasatch is approaching northern
Announcements
The Wasatch Powderbird Guides did not fly
yesterday due to weather and won’t get out today. For more detailed information please call
(801) 742-2800 or go to their daily
blog.
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.
Brett Kobernik will update this advisory by 7:30 on Monday morning.