Wasatch Cache National Forest

In partnership with: The Friends of the Utah Avalanche Center, Utah Department of Public Safety Division of Comprehensive Emergency Management, Salt Lake County, and Utah State Parks

 

: http://www.avalanche.org/~uac/

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Avalanche advisory

WEDNESDAY, DECEMBER 17, 2003   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 Wednesday December 17th, 2003, and it’s 7:30 a.m. 

 

We’re giving a free avalanche awareness talk on Thursday, the 18th, at the Sandy REI at 7pm.

 

Current Conditions:

Today is another good day to call in sick from work.  Temperatures have warmed rapidly as the high pressure ridge builds over us.  Temperatures along the ridge tops are 20 degrees warmer this morning than yesterday morning and they are in the mid to upper 20’s with a 10-20 mph wind from the west.  There’s still plenty of delightful powder snow, about a foot deep, on all the slopes facing the north and east quadrants of the compass today, but the south facing slopes have a sun crust on them from yesterday.  With high pressure and warm temperatures expected for the rest of the week, the snow conditions should progressively deteriorate.  

 

Avalanche Conditions:

Yesterday, a lot of people jumped into steep slopes of all kinds and there was only one human triggered avalanche we know of.  Early yesterday morning, a lone skier triggered a soft slab avalanche in Toledo Chute, which is an east-southeast facing slope across the street from Alta.  We don’t have a first hand report, but the tracks tell most of the story.  Luckily it broke at their feet and they were not caught, but it entrained copious amounts of snow and put down a very deep debris pile at the bottom you wouldn’t want to be buried in.  The fracture was about a foot deep, 40 feet wide on a steep 40-45 degree slope and it broke either just above or just below the rain crust from last Saturday.  Click HERE for photos.   In general, though, the weak layers seem to have adjusted to their loads and the snow remains well behaved after being skied and ridden by many dozens of volunteer stability testers.  I’m still worried, however, about some of the steep slopes with wind deposits, mostly on the above tree line, wind exposed ridges where they still feel slabby and suspicious to me.  Also of note, if you’re headed outside of the Salt Lake area mountains, as our staff has gotten out after the storm, we’ve noticed several large natural avalanches that occurred on Monday in shallower snowpack areas.  In Logan, one avalanche broke 4 feet deep and 300 feet wide on an old layer of faceted snow and in the Uinta Mountains there were a number of smaller pockets breaking to the ground on depth hoar.  These areas with a shallower snowpack may be a notch higher on the avalanche danger scale than in the Salt Lake Mountains.  Be sure to check the local advisory before you go.   By the way, if you get out early, each day we update our more detailed and early morning report with preliminary information at 6:00 am at (801) 364-1591.

 

Bottom Line (Salt Lake and Park City, Ogden and Provo mountains):

In isolated, steep, slopes with deposits of wind drifted snow, the danger is MODERATE today.  You will find these mostly on very high, wind exposed ridges.  On non wind-loaded slopes the danger is generally LOW.

 

Click here for a photo of a small human triggered slide in the Provo area mountains on 12/15/03.

 

Mountain Weather:

We will have one of those warm, high pressure ridges over us for the rest of the week, which will bring very warm temperatures to the mountains and smog in the valley.  The high today along the ridge tops should get up into the lower 30’s and into the lower 40’s down at 8,000’.  Ridge top winds should remain light from the west, turning southwest later in the day and tomorrow.   We should have a few high clouds go by today and tomorrow.  The extended forecast calls for a weak disturbance on about Friday and a somewhat stronger one on Sunday.

 

3-Day Table

3-Day Graph

7-Day Table

Ogden Mountains

Ogden Mountains

Ogden Mountains

SLC Mountains

SLC Mountains

SLC Mountains

Provo Mountains

Provo Mountains

Provo Mountains

 

For specific digital forecasts for selected mountain areas from the National Weather Service, click the links below or choose your own specific location at the National Weather Service Digital Forecast Page:

 

General Information:

Yesterday, the Wasatch Powderbird Guides flew in Cardiff and Days with a home run on Patsy Marly and Emma Ridges.  Today they plan to fly in Mineral, Cardiff, Days and Silver with an avalanche class in White Pine.

 

If you are getting into the backcountry, please give us a call and let us know what you’re seeing, especially if you trigger an avalanche.  You can leave a message at 524-5304 or 1-800-662-4140.  Or you can e-mail an observation to uac@avalanche .org, or you can fax an observation to 801-524-6301.

 

The Friends of the Utah Avalanche Center is offering two 3-day avalanche workshops which are being held January 17-19 and February 14-16.  Information and sign-up sheets are available at the Black Diamond store (2092 E. 3900 S.; 278-0233).

 

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 on Thursday morning.

Thanks for calling.

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For more detailed weather information go to our Mountain Weather Advisory

National Weather Service - Salt Lake City - Snow.

For an explanation of avalanche danger ratings:

http://www.avalanche.org/usdanger.htm