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

thursday, DECEMBER 25, 2003†† 7:30 am

 

Merry Christmas, this is Bruce Tremper with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory.Today is Christmas Day, December 25th, 2003, and itís 7:30 a.m.

 

Current Conditions:

Itís an old tradition around here to give you a Christmas poem as the avalanche advisory, but today things are nearly too complicated for prose, much less verse. Nevertheless, I will put some sort of lame facsimile of a poem on the other recording at 364-1591 or click HERE for the web version. Yesterday, the winds howled in the upper elevation terrain turning all our nice snow into sand-blasted areas alternating with dunes of dense, stubborn, wind slabs that would nearly rip your leg off when you hit them with the added bonus of some flying swan dives. Down lower in the more wind sheltered trees, the winds left things alone and there was six inches of sugary faceted snow and surface hoar that felt like powder if you didnít know better. This morning, temperatures are in the mid 20ís along the ridge tops with 20 mph winds from the southwest. About five inches of snow have fallen as of 7:00 am this morning but thereís lots more on the way.

 

Avalanche Conditions:

I heard about three different natural avalanches yesterday from wind drifting.One was in upper Little Cottonwood Canyon, one near Park City and one on the north side of Timpanogos that made lots of noise as it descended. There was also a skier triggered avalanche in Dayís fork on an east facing slope at 10,500í, which broke a foot deep and about 15 feet wide. The skier skied off the slab and was not caught. All of these slides were wind slabs and slid either within the new snow or broke down to the rain crust from the 13th thatís dirty brown in many areas. The trouble is that as today, as the new snow accumulates, it will make yesterdayís wind slabs invisible.As always, be suspicious of smooth, rounded snow on steep slopes that feels slabby and sounds hollow.

 

The second problem today will be the new snow. Iíve had some reports this morning that the new snow is not bonding very well to the old snow surfaces. So as the snow accumulates, be sure to jump on lots of small test slopes and test how well the new snow is bonded to the underlying layers by digging down often with your hand as you travel. Also, wind will create a fresh round of wind slabs within this new snow today, mostly along the upper elevation ridges but it could be lower on the slopes as well. Also, the old snow surface in wind sheltered, shady slopes was mostly very weak faceted snow and surface hoar, so as the new snow piles up, some of the most sensitive and dangerous areas may be innocuous-looking places like gullies and terrain traps down low in the basin bottoms.

 

This storm looks like a big one and we may pile up copious amounts of new snow through about Tuesday. As the weight adds up, avalanches within the new snow could start to step down to deeper weak layers, making much larger avalanches.

 

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

The avalanche danger is rising rapidly today and especially tomorrow. Although thereís only aMODERATE danger this morning, it will likely rise to CONSIDERABLE this afternoon as we accumulate snow.By Friday night, we may have a couple feet of new snow with more on the way and the danger may rise to HIGH especially in areas with a thinner snowpack.

 

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:

Thereís not much not to like about this weather forecast unless youíre a holiday traveler who needs to drive someplace. A major winter storm is starting this morning and weíre expecting about a foot of snow in the mountains today and another foot of snow on Friday. Ridge top winds will blow 15-20 from the southwest with temperatures in the mid 20ís. Down at 8,000í temperatures should be just below 30.The cold air will arrive about mid day Friday and the winds should turn northwest and the temperatures will plummet. By Saturday morning, temps will be down around 0 degrees along the ridges. For the extended forecast, storms will continue to bring more snow through about Tuesday

 

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.

 

Like I say, you can get the Christmas poem by calling (801) 364-1591.

 

If you are getting into the backcountry, please give us a call and let us know what youíre 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 [email protected] .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.

 

Andrew McLean will update this advisory on Friday 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