Wasatch Cache National Forest
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 Salt Lake County.

keeping you on top

AVALANCHE ADVISORY

Thursday, March 01, 2007  7:30 am
Good morning, this is Bruce Tremper with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory.  Today is Thursday, March 01, 2007 and it’s 7:30 in the morning.

 

Current Conditions:

Our apologies.  The Internet-based advisory is late this morning because of computer network problems at the National Weather Service

About 4 inches of new snow fell overnight and you will want your down coat, mittens and face mask today because the ridge top temperatures are between zero and 5 degrees with a stiff west-northwest wind blowing 20 gusting to 40 along most of the ridge tops and 40 gusting to 60 on the most exposed peaks.  We’re expecting snow for most of today, tonight and Friday morning.

 

Snow and Avalanche Discussion:

Yesterday Evelyn suggested that everyone do some sightseeing to marvel at some of the huge, natural avalanches that occurred Tuesday.  Sure enough, many folks had a memorable day and they e-mailed us dozens of spectacular photos last night from throughout northern Utah.  It will take me most of the rest of the day to get them posted on our photo page and update our avalanche list.  I will list as many natural avalanches from Tuesday’s storm as I can on our early morning, telephone recording (888-999-4019 option 8).  Although most of the deep, natural, monster-avalanches from the backcountry seem to have subsided, avalanche control from Snowbasin produced three huge, deep, nightmares fracturing to the ground up to 8-15 feet deep and several hundred feet wide.  These were from single shots in the right spot, which theoretically a person could trigger if they tickled the right spot. 

When people trigger these large avalanches, they typically do so where the slab is thinner, such as mid slope near rocks, or they drop a big cornice on the slope.  Once it starts ripping, it can propagate into deep, hard layers making very large avalanches.  The problem exists mostly on slopes that face the north or east quadrants of the compass.  Once again, these big mommas may be hard to trigger but if you do, it’s definitely the nuclear option.

Also, yesterday there was a remotely-triggered avalanche in American Fork when the WPG helicopter set down on a ridge top landing zone around 9,500’.  It broke out on an adjacent, steep, north facing slope they never ski and it broke 2-3 feet deep and 200 feet wide into faceted snow.

 

Probably more importantly today, we have new snow with strong wind, which will certainly make sensitive wind slab avalanches on any steep slope with recent wind drifts.  Some of these new snow avalanches have the potential to step down creating larger and more dangerous avalanches especially on north through east facing slopes.

Bottom Line for the Salt Lake, Park City, Provo and Ogden area mountains: 

Today we will have a CONSIDERABLE avalanche danger on any slope approaching 35 degrees or steeper with recent deposits of wind blown snow.   There is also a lingering  CONSIDERABLE danger on slopes 35 degrees or steeper, facing northwest, north, northeast, east and southeast above about 8,000’.  Considerable danger means human triggered slides are probable.  Both new snow slides and deep, unsurvivable slides breaking to the ground can be triggered by people.  People without excellent avalanche skills should avoid backcountry travel today.  Today is another good day for a ski resort.  High marking is not recommended.  The avalanche danger may rise to HIGH tonight and on Friday.

 

Mountain Weather: 

The mountains should continue to get snow throughout the day with another 4-8 inches, probably intensifying by mid day or afternoon.  Ridge top winds will continue to blow 25 from the west and northwest with gusts to 40.  On the highest, most exposed peaks, winds will blow 35 gusting to 55.  Ridge top temperatures will be chilly, around 5 degrees.  Snow should end later on Friday but the winds will pick up and blow harder. 

The extended forecast calls for a warm and sunny weekend with the chance for another storm on about Wednesday.

Announcements:

The Wasatch Powderbird Guides flew yesterday in Cardiff, Days, Silver, Grizzly and American Fork and they will not be able to get out today due to weather.  With questions regarding their areas of operation call 742-2800.

 

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 all the great snowpack and avalanche observations we’ve been getting, so keep leaving us messages 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.

Evelyn Lees will
update this advisory by 7:30 on Friday morning, and thanks for calling.