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

Saturday, March 01, 2003

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Good Morning. This is Bruce Tremper with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory. Today is Saturday, March 01, 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:

With snow just beginning in the mountains this morning, the Ogden area mountains have 3 inches of new snow so far and the Salt Lake Area Mountains have just started with about an inch so far. I’m expecting about 2-4 inches of new snow today. Yesterday, a sun crust formed on the surface of the south facing slopes and there’s still 4-8 inches of nice powder on the slopes that face the north half of the compass.

Avalanche Conditions:

For the weekend warriors, here’s a synopsis of the past week:

If you remember last Saturday, exactly a week ago (here, imagine wavy lines across the screen and harp music) we had extremely strong northwest winds with 1 – 1 1/2 feet of new snow on Saturday and Sunday. Not surprisingly, we had quite a number of avalanches from wind-deposited slabs and quite a few of them broke into deeper layers of weak, faceted snow. All told, there were 15 unintentional human triggered avalanches in the backcountry this past week with perhaps twice that number of intentionally triggered avalanches. Although we have not had any reports of avalanches from yesterday, on Thursday there were three large avalanches triggered from backcountry explosive testing in the Salt Lake Area Mountains, one of which took out 40 old ski tracks and a climbing trail. The last unintentional human triggered avalanche was on Wednesday and very large natural avalanches occurred as recently as Wednesday in the high Uinta Mountains. (For more details you can look at the list of avalanches and some impressive photos of many of these avalanches at the usual location: www.avalanche.org~uac/.)

The stock market has dozens of indices, which indicate sentiment of consumers and traders and I use my own index of avalanche danger, which I call the Cagy Old Avalanche Professional’s Pucker Factor. In my informal survey these past couple days, the Pucker Factor is running at around 90 percent, meaning that 90 percent of the old timers are not willing to mess around with steep, backcountry terrain right now. Although the probability of triggering one of these deep, huge monsters is low, the consequences are considerable, which averages out to a moderate danger rating. Almost all of the recent, large avalanches have occurred on steep slopes with a shallow snowpack, especially on avalanche paths which have slid already this season. So be especially suspicious of places which fit this description. The deeper snowpack areas are fairly stable, but you have to do a lot of poking around to tell the difference.

As far as the new snow, the top few inches is very weak and sluffs easily in shallow, loose snow avalanches, which are not too dangerous unless one takes you over a cliff or into a gully.

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

The avalanche danger is MODERATE on slopes steeper than about 35 degrees with a thin snowpack, above about 9,000 feet that face the north half of the compass, plus east facing slopes. Although the probability of triggering avalanches on these slopes is low, the avalanches will be large and dangerous. Slopes less steep than about 35 degrees have a generally LOW danger. 35 degrees is about the steepness of a black diamond slope at a ski resort. Remember most people overestimate slope steepness by 5-10 degrees, so be sure to measure them.

Note: the western Uinta Mountain have a CONSIDERABLE danger above 10,000 feet and is significantly more dangerous than the Wasatch Range. We’re especially worried about snowmobilers in the high Uinta Mountains today. Western Uintas – call 1-800-648-7433 or click here for weekend and holiday forecasts.

Mountain Weather:

This broad trough over the western U.S. is rotating occasional pulses of moist, unstable air into us from the west. Today we will have one of these pulses with light snow showers and 1-4 inches of light density snow through the day. Ridge top winds will be fairly light, around 10 mph from the west and turning north by tonight. 11,000’ temperatures will remain cold, 5-10 degrees today and down at 8,000’ the high should be around 20 degrees. For the extended forecast, Sunday and Monday should be clear with more snow for the remainder of the week.

General Information:

Wasatch Powderbird Guides will probably not fly today because of the weather, but if they do, they may fly in Days, Silver, Cardiff, White Pine and American Fork, depending on visibility.

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.

Ethan Greene will update this advisory by 7:30 on Sunday 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