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.

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AVALANCHE ADVISORY

Sunday, March 04, 2007  7:30 am
Good morning, this is Drew Hardesty with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory.  Today is Sunday, March 04, 2007 and it’s 7:30 in the morning.

A SPECIAL AVALANCHE ADVISORY CONTINUES FOR THE MOUNTAINS OF
 NORTHERN UTAH. RECENT HEAVY SNOW AND STRONG WINDS HAS LED TO
 DANGEROUS AVALANCHE CONDITIONS ON STEEP MOUNTAIN SLOPES. LARGE
 UNSURVIVABLE AVALANCHES HAVE RELEASED OVER THE PAST TWO DAYS.
 THOSE WITHOUT EXCELLENT AVALANCHE AND ROUTE FINDING SKILLS SHOULD
 AVOID THE BACKCOUNTRY.

 

Current Conditions:

Skies are clear with the full moon just starting to wane.  The northerly winds are generally light and the mountain temperatures……will be the issue for today.  Temperatures this morning are universally 20-25 degrees warmer than they were 24 hours ago.  They’re in the low to mid-twenties with colder readings in the drainages and mountain basins.

 

Snow and Avalanche Discussion:

For an avalanche forecaster, it’s an embarrassment of riches with all the activity during and since the natural cycle Thursday night into Friday morning.  And, as far as we heard, no real close calls or incidents.  It has been, thankfully, a ghost town in many of the backcountry areas, and I appreciate folks’ discipline in avoiding or tip-toe-ing around the more exposed avalanche prone-terrain.  We did hear about a skier-released avalanche in the Upper Mary Chutes in the Brighton backcountry up to 3’ deep, but details were few.  Another party triggered a massive cornice along the Wolverine Cirque, pulling out a monster down below 4-7’? deep and a couple hundred feet wide.  Explosive testing by the Wasatch Powderbird Guides from the helicopter for protection of Big Cottonwood Canyon and elsewhere in the backcountry produced massive slides up to 4-6’ deep with many described as ‘wall-to-wall’.  The lead UDOT forecaster in BCC, who makes an art out of the understatement, described yesterday’s explosive release-avalanche in Stairs Gulch as ‘impressive’.  It ran within 1000’ of the road.  Many other photos keep piling in and can be found on our photos page here.

 

It’s been just 48 hours since the havoc of the early Friday avalanche cycle, and I was looking forward to increasing stability and a pockety avalanche problem.   With the rapid overnight warming and a nod to old Peter Lev, all bets are off.  10,000’ temperatures enroute highs in the low thirties, light winds, and a high sun will conspire to exacerbate the shear stress within our already shell-shocked snowpack.  By tugging the slab downhill through rapidly increasing the creep rate and then softening the slab for human-triggerability, the temperatures will play the starring role in avalanche activity today.  Its effects are less well understood than additional snowfall or strong winds, put it’s a player all the same.  There will be plenty of wet activity on the sun-exposed slopes today, but the effects I’m laboring to describe will be most pronounced on the northwest through easterly aspects – the terrain with the weak underlying snowpack.  Exercise caution yet another day.

 

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

The avalanche danger is CONSIDERABLE today on slopes approaching 35 degrees and steeper on northwest through the easterly aspects.  Large natural avalanches will be possible with daytime warming.  Human triggered slides will be probable with sensitivity peaking with daytime warming.  The danger of wet avalanche activity will rise to CONSIDERABLE on all steep sun-exposed slopes.  Cornices will be sensitive so give them a wide berth.

 

Mountain Weather: 

We’ll see mostly clear skies with a few clouds during the day today.  The winds will back to the west but remain generally light.  We’ll see a weak disturbance late Monday with another system possible for late Thursday.

 

Announcements:

The Wasatch Powderbird Guides flew in Cardiff, Silver, Grizzly, and American Fork, and today will be in AF, Snake Creek, the Sessions and Lambs.  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.

I will
update this advisory by 7:30 on Monday morning, and thanks for calling.