Wasatch Cache National Forest

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

The Utah Avalanche Center Home page is: http://www.avalanche.org/~uac/

Avalanche advisory

Friday, March 07, 2003

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Good Morning. This is Tom Kimbrough with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory. Today is Friday, March 07, 2003, and it’s 7:30 in the morning. We would like to acknowledge one of our partners, the Friends of the Utah Avalanche Center, generously supported by Alta Ski Lifts.

Current Conditions:

Strong winds continue to blast the Wasatch with overnight speeds of 20 to 50 mph. 24 hour snow totals are only a few inches. Storm totals are 24 to 30+ inches in the Cottonwoods, 1 to 2 feet on the Park City side, with 1 ½ feet in the Ogden mountains, and about a foot at 7,500’ in the Provo mountains. Temperatures are in the upper teens and low twenties. The new snow is heavy and inverted, with lighter snow underneath heavy snow. Trail breaking is very difficult and many slopes have extensive wind damage.

Avalanche Conditions:

Again yesterday, despite poor visibility, numerous natural, remotely triggered and human triggered slides were reported from the backcountry. One very experienced avalanche worker was caught when lower Toledo Gully north of the Little Cottonwood road broke back farther than expected with a 6 foot deep fracture. He was on the top end of the avalanche and was not injured but this is an indication of just how tricky conditions are. Slides are breaking on slopes of 30 degrees and also pulling out adjacent lower angle terrain and overrunning normally safe places. Fractures are mostly 1 to 3 feet deep and 50 to 100 feet wide but several have broken much deeper and over 500 feet wide. I’ll have details on the 364-1591 line by about 9:00 a.m. Check out these photos of recent slides. (Photo 1 - Willows) (Photo 2 - Thaynes )

Avalanches have released on all aspects, at lower elevations and well off ridgelines especially on terrain features such as gully walls and sub ridges. Even at low elevations, isolated pockets of wind drifted snow can be triggered in steep gullies and on rollovers that have seen wind drifting from strong low elevations winds. Out of wind affected terrain sluffing and soft slabs up to 2 feet deep are possible on any steep slope. Cornices are large and very sensitive, breaking farther back than expected.

Avalanches in the drifted snow may break into deeper weak layers, creating much larger and more dangerous slides. These deeper slides are possible on slopes of all aspects but especially on steep, rocky slopes with a thin snowpack.

If skies clear much today, there will be a rapid rise in the avalanche danger on all sun exposed slopes.

Bottom Line (SLC, Park City, Ogden and Provo Area Mountains):

The avalanche danger is HIGH on and below all slopes with recent drifts of wind blown snow steeper than about 30 degrees. Natural and human triggered avalanches are likely. People should avoid steep backcountry terrain and avalanche run out areas. Avalanches are also possible on steep wind sheltered slopes.

Bottom Line (western Uintas): The largest and most numerous avalanches have been reported from the Uinta Mountains. There is a HIGH avalanche danger on, adjacent to and below all steep slopes.

Western Uintas – call 1-800-648-7433 or click here for weekend and holiday forecasts.

Mountain Weather:

The last in the current series of disturbances will brush the Wasatch this afternoon. Skies will be mostly cloudy with occasional snow showers and accumulations of around 1 to 3 inches (2-4 Ogden). Winds will stay strong perhaps into Saturday with speeds of 20 to 40 mph from the west. High temperatures will reach the low to mid thirties at 8,000 feet and will be in the twenties at 10,000. High pressure will begin to build for the weekend with clearing skies and warmer temperatures on Saturday and Sunday.

General Information:

Wasatch Powderbird Guides will probably not be flying today because of weather but if they do get out, they plan to fly one ship in Cardiff, Days, Silver and White Pine with a homerun in Grizzly Gulch. A second ship would go to American Fork. To speak with a WPG guide, call 801 742-2800.

To report backcountry snow and avalanche conditions, especially if you observe or trigger an avalanche, please leave a message on our answer machine at (801) 524-5304 or 1-800-662-4140, or email to [email protected] or fax to 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.

Bruce Tremper will update this advisory by 7:30 on Saturday morning.

Thanks for calling!

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National Weather Service - Salt Lake City - Snow.

For an explanation of avalanche danger ratings:

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