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”
February 10, 2007 7:30 am
Good morning, this is Evelyn Lees with the
a new look to our avalanche advisory thanks to the design work by
A weak warm front
moved through just before dawn, bringing cloudy skies and a trace to an inch of
snow to the mountains, mostly north of I-80.
Winds are from the west southwest, generally in the 5 to 10 mph range,
with a few of the most exposed locations having overnight averages of 15 to 30
mph. Temperatures continue to be unseasonably
warm, in the mid 20’s at 10,000’, with a band of above freezing temperatures
between about 6,500’ to 8,000’. The old snow surface mostly consists of crusts,
ranging from thin zipper crusts, to breakable to icy hard.
Snowpack and Avalanche Conditions:
This will be a weekend of increasing avalanche danger, and the insightful Tom Kimbrough always felt periods of rising avalanche danger were some of the trickiest and most dangerous times for backcountry travelers. This winter’s “powder drought” and unusually weak, variable snowpack will make it doubly hard to evaluate the changing conditions.
Yesterday, 4 small
slides were triggered in the Provo area mountains, including a small
3” deep hard slab 8 feet wide and two similarly small soft wind drifts, all
breaking on super weak facets and a facet sluff. Many locations have a similar snow pack, with
crust precariously balanced on top of ridiculously weak
facets. Today, it will be possible
to trigger comparable slides – loose sluffs in the facets, hard crusts, and old
wind drifts - in isolated areas. Remember,
the weak faceted snow exists on just about every aspect, every elevation,
either at the surface or shallowly buried beneath thin crusts or old hard wind
drifts, so any slopes of about 35 degrees or steeper should be approached with
caution. In areas with the hard drifts or crusts, these
slides can be triggered remotely or will often break out above you, which means
even these 4” deep slides will knock you off balance and have the potential to
take you for a ride in steep terrain. Once a slide starts, it has the potential to
break into deeper layers, becoming wider or gouging down into the loose, sandbox
snow. The weakest snow is on northerly through
southeasterly facing slopes, and in the shallower snowpack areas, which are
most widespread, but certainly not limited, to the
Bottom Line for the
This will be a weekend of increasing avalanche danger. This morning, there is a MODERATE avalanche danger on all slopes approaching 35 degrees or steeper, especially those with fresh or old deposits of wind drifted snow and the low to mid elevations due to warm temperatures. The avalanche danger will increase to CONSIDERABLE this afternoon or evening as soon as additional snow or rain starts to fall, rising fastest on slopes where the southwesterly winds drift the snow.
A moist southwesterly
flow will bring a series of weather disturbances across
Yesterday, the Wasatch Powderbird Guides did not fly, and in the unlikely
event they fly today, they will be in
Listen to the advisory. Try our new streaming audio or podcasts
UDOT highway avalanche control work info can be found HERE or by calling (801) 975-4838.
Our statewide tollfree line is 1-888-999-4019 (early morning, option 8).
For a list of avalanche classes, click HERE
For our classic text advisory click HERE.
To sign up for automated e-mails of our graphical advisory click HERE
We appreciate any snowpack and avalanche observations you have, so 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.
Drew Hardesty will update this advisory by 7:30 on Sunday morning, and thanks for calling.