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

Friday, DECEMBER 26, 2003   7:30 am

 

Good morning, this is Andrew McLean with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory.  Today is Friday, December 26th, 2003, and it’s 7:30 a.m. 

 

Current Conditions:

We had a slight lull in our storm system yesterday, and then it returned with a vengeance to deliver current storm totals of 28” in Little Cottonwood, 29” in Big Cottonwood, 24” in the Ogden area mountains and 22” in the Provo area mountains.  And it’s far from over – another 10-14” are expected by the end of today. So far, this has been a fairly warm storm system, with temperatures in the mid to high 20’s, which has produced moderate density snow in the 8-11% range, that makes for slow trail breaking, plush turning and riding conditions and  a deep base.  With all of this new snow, the trick for today will be finding slopes that are steep enough to move on, yet not so steep they will avalanche.

 

Avalanche Conditions:

Although we might be in the Christmas season, the snowpack is pure Halloween.   There is wide spread natural avalanche activity being reported from the resorts, with large sluffs and soft slabs running full track and ending in deep debris piles.  With 2.5” of water weight being deposited in the last 48 hours we have added a huge new load to the snowpack.  Underneath all of this, there are a series of slabs and potential weak layers stacked up, and with this sudden increase in loading, there is a good chance that shallower avalanches in the new snow could step down into deeper layers and trigger large avalanches.  With the ridgetop winds yesterday, sensitive cornices are forming with wind loaded pillows beneath them.  These recent deposits of wind drifted snow will be very sensitive to a person’s weight. 

 

Today, expect to easily trigger avalanches anywhere from small powder sluffs to deep soft slab avalanches especially in wind affected areas.  Until the storm abates, it will be a good idea to stick to sheltered, mid elevation areas with slope angles of less than 35 degrees and avoid avalanche run-out zones.  

 

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

With natural and human triggered avalanches already occurring, there is a HIGH danger today on any slope steeper than 35 degrees.  In wind sheltered areas with slopes less steep than 35 degrees, there is a CONSIDERABLE danger, with human trigger avalanches probable.  People without good avalanche skills should avoid the backcountry today.

 

Uinta Mountains:  A specific advisory for the Uinta mountains is being issued today.  Click on western Uintas on the advisory page or phone 1-800-648-7433.

 

Mountain Weather:

Today the storm will intensify as a cold trough moves over the area and brings a heavy snow warning with another 10-14” of new snow expected at 8,000’. As of 6:00am, the 8,000’ temperature is 18 degrees with a 10mph wind coming out of the SW.  The moderate winds will shift from the SW to the NW with occasional strong gusts and a chance of lightning.  We can expect a slight reprieve in the snowfall intensity at sunrise, only to have it kick back in as the storm shifts to a NW flow and temperatures drop into the lower teens by mid morning.  24 hour storm totals for today are expected to be in the 16-23” range, with heavy snowfall throughout the day and into this evening.  The storm will most likely shift to the east on Saturday, with the next one following it in from the Pacific on Monday.

 

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.

 

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

 

 

General Information:

The Wasatch Powderbird Guides will not fly today because of weather.

 

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. 

 

Drew Hardesty will update this advisory on Saturday morning.

Thanks for calling.

_____________________________________________________________________________

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