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 National Weather Service has issued a
Winter Storm Warning for the mountains of
Avalanche Conditions: An observer reports a recent large hard slab avalanche on the
Richmond Bench, but details as to when and why this happened are lacking. I’d love to hear more, and any additional
information you might have would be greatly appreciated. Strong winds blasted the region last week
leading to a fairly widespread natural avalanche cycle, (photos). Other, more recent local activity includes continued
loose wet avalanches at lower elevations and large cornice falls up high. Large
cornices are still somewhat sensitive and are likely to become more so as they
build anew today.
Strong northwest winds accompanying heavy snowfall will rapidly build
shallow wind slabs in the midst of today’s intense storm. The wind slabs may not bond well with the old
snow surface, which is plagued by a rime crust and in some places, well
developed frost crystals or surface hoar. Of course, the danger this afternoon will be
highest in areas that receive the most snow and wind, with slabs building up on
steep slopes and in avalanche starting zones.
Although most wind slabs will be fairly small today, they could well be
long running and quite fast moving on well smoothed out and slick run-outs or
avalanche paths…
Last week slabs formed on a few slopes plagued by buried
persistent weak layers and although now fairly unlikely, there’s still a
possibility that you might trigger a dangerous hard slab avalanche in places. I’m still leery of lower elevation slopes
with generally shallow and hence, weaker snow. The recent avalanche on the Richmond Bench may
fit into this category.
Bottom Line: During today’s storm, the danger will rise to MODERATE on steep drifted slopes in the backcountry, and you
might trigger wind slab avalanches. More
than expected snowfall and/or sustained strong winds may cause the danger to
rise to CONSIDERABLE in a few upper elevation pockets by late afternoon. Avoid obvious drifts on steep slopes and use
good snow assessment and safe travel techniques to minimize your risk.
Mountain Weather: Radar
returns depict a band of precipitation moving into
General Announcements:
This advisory will expire
in 24 hours from the posting time.
Check out the images page for photos of some of
last week’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.
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.
