Wasatch Cache National Forest
In partnership with: Utah Division of State Parks and Recreation, The Friends of the Utah Avalanche Center, Utah Department of Emergency Services and Homeland Security and Salt Lake County.

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AVALANCHE ADVISORY

Wednesday, February 13, 2008 7:30 am
Good morning, this is Evelyn Lees with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory. Today is Wednesday, February 13, 2008 and its about 7:30 am.

 

Current Conditions:

The southwesterly winds are picking up this morning, ahead of an intense cold front that will reach the northern mountains early this afternoon. Wind speeds are in the 20 to 30 mph range, with gusts in the 40s. Temperatures are also increasing, currently in the upper 20s at 10,000. Travel conditions are fast and fun with supportable snow on most aspects, and good turning and riding conditions on northerly and easterly facing slopes in windblown and recrystalized powder over a dense, carvable base.

 

Snow and Avalanche Discussion:

This morning, before the arrival of the storm, the snowpack is generally stable, with just a few isolated avalanche concerns. It will be possible to trigger damp sluffs on steep slopes, mostly at the lower elevations, and both cornices and new wind drifts could be sensitive, with the cornices breaking back further than expected.

 

Avalanche conditions will change rapidly with the arrival of the cold front early this afternoon. Possible lightning, strong winds, and a period of very high snowfall rates for several hours will combine to create both dangerous travel conditions and an increasing avalanche danger. As the new snow accumulates or drifts to depths of about 6 inches or more, it will become possible to trigger new snow soft slabs on steep slopes. The bonding of the new snow to the old snow could initially be poor on hard slick crusts or old wind slabs, and on slopes where the surface hoar is preserved and buried. Ski or slope cuts on small test slopes will be a good stability testing tool today. Sluffs and slides triggered in long gullies or on continuously steep slopes, like those in the Provo area mountains, could be surprisingly long running.

 

Bottom Line for the Ogden, Salt Lake, Park City and Provo area mountains:

The avalanche danger is mostly LOW this morning, though it will be possible to trigger sluffs in the damp low elevation snow, and wind drifts and cornices at the higher elevations. The avalanche danger will rapidly rise to MODERATE this afternoon with the arrival of the cold front, and sensitive human triggered new snow sluffs and slides will be possible on slopes of about 35 degrees and steeper, especially where wind drifted.

 

Mountain Weather:

Appearances can be deceiving this mornings warm, spring like conditions will rapidly change when a strong cold front sweeps into the area mid afternoon, with near blizzard conditions. Ahead of the front, the southwesterly winds will increase into the 25 to 35 mph range, with gusts into the 50s and 60s, and temperatures warming into the low 30s at 10,000. After the arrival of the intense cold front, several hours of heavy snowfall should produce 6 to 9 inches of snow by evening. The winds will shift to the northwest, still averaging 25 to 35 mph. Temperatures will plummet into the single digits behind the front. A few more inches of snow possible tonight, with storm totals of 6 to 12 inches likely. Cold and mostly clear on Thursday, followed by a dry and warming trend for the weekend into early next week.


Announcements

Yesterday,
Wasatch Powderbird Guides flew in Cardiff, Days, Silver, Grizzly, Lambs, the Sessions, and if the winds allow, today they will be in Mineral, Cardiff, Days, Silver, Grizzly, White Pine and American Fork. For more detailed information please call (801) 742-2800 or go to their daily blog.

 

There are a few spots left in the Friends of the Utah Avalanche Centers Brighton Level 1 Avalanche class, February 16-18. For more information, call 278-0233.

 

For folks with an Alta pass, ACE (Alta Community Enrichment) is offering an avalanche awareness class the evening of Feb 12 and 13, and day the 16th, for $25. Pre Register at [email protected].

 

If you want to get this avalanche advisory e-mailed to you daily click HERE.
UDOT highway avalanche control work info can be found by calling
(801) 975-4838.
Our statewide tollfree line is 1-888-999-4019 (early morning, option 8).

The UAC depends on contributions from users like you to support our work.  To find out more about how you can support our efforts to continue providing the avalanche forecasting and education that you expect please visit our Friends page.

If you see any avalanches or interesting snow conditions, please leave us a message at
(801) 524-5304 or 1-800-662-4140, or email us at [email protected]. (Fax 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 Thursday morning.