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

Tuesday, December 04, 2007  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 Tuesday, December 04, 2007 and it’s about 7:30 am.

 

Current Conditions:

Under mostly cloudy skies, temperatures are ridiculously warm this morning, in the mid 30’s to mid 40’s from 8,000’ to the tops of the highest peaks.  Winds are from a westerly direction, averaging 10 to 15 mph, with gusts in the 20’s.  In the highest terrain, speeds are 25 to 35mph, with gusts in the 40’s.   

 

Warm temperatures and wind are shrinking the areas of decent powder, limiting it to shady, wind sheltered terrain at the upper elevations, above around 9,500’.  Most other slopes have damp, crusted, or wind damaged snow, not to mention a snowpack so shallow that hitting rocks is a given.  Snow packed roads and trails, and grassy high elevation meadows will provide the least rocky riding conditions for snowmobiles.  Be cautious so you don’t have a season ending encounter with a rock. 

 

Avalanche Discussion:

There were no new reports of avalanches in the backcountry yesterday, to some extent due to a lack of triggers.  However, the Cottonwood resorts continued to have very good results with explosives, triggering several avalanches 1 to 3 feet deep, up to 150’ wide, failing on the layer of faceted weak snow. 

 

These slides fit the current pattern of instability – steep, upper elevation, northerly facing slopes where the storm snow is underlain by old, sugary, October snow.  And today, it continues to possible for a person to trigger a slide 1 to 2’ deep and 100’ wide on one of those northerly facing slopes. Slides may have the tendency to break out above you because some of the weakest snow is off the ridgelines and on mid slope breakovers.  So watch your slope angles.  Staying off of and out from under slopes steeper than about 35 degrees is one way to avoid triggering a slide on those shady slopes.  For a look at the snowpack around two of the recent slides, click here and here.

 

Today’s other avalanche concern will be any fresh drifts of wind blown snow.  These drifts will be most widespread along the higher ridges, but also watch for drifting around terrain features such as breakovers, rocks and subridges.  Avoid any of the rounded, pillowed drifts on steep slopes.

 

Bottom Line:

Salt Lake, Park City and Provo area mountains: The avalanche danger is MODERATE on northwest, north and northeast facing slopes steeper than about 35 degrees above about 9,000’ in elevation. Human triggered avalanches are possible, and in isolated places a person could trigger a slide from a distance.  Also avoid any new drifts of wind blown snow, which will be most widespread along the higher ridgelines.

 

Ogden area mountains: The avalanche danger is generally LOW due to the lack of faceted snow.   However, today’s stronger winds may create some sensitive drifts along the higher ridgelines.

 

Mountain Weather: 

A series of weak, fast moving storms will cross northern Utah today through Thursday, with a stronger storm impacting the area Friday into the weekend. Today’s weak disturbance will bring light rain and snow showers to the mountains, with the rain/snow line starting out near 8,000’.  Snowfall amounts will be minimal - a trace to 1” possible south of I-80, with up to 2” possible to the north of I-80.  Mountain temperatures will be in the upper 30’s and low 40’s this morning, gradually cooling to near freezing by this evening.  The westerly winds will increase into the 20 to 30 mph range, with gusts to near 40.  Along the highest peaks and ridges, sustained speeds will be in the 30’s.  Wednesday will bring cooler temperatures and another chance for light snow showers.

 

Announcements:

 

For an avalanche education class list, click HERE.  

 

If you want to get this avalanche advisory e-mailed to you daily click HERE.

 

The UAC has job openings.  Click HERE for info.

 

UDOT highway avalanche control work info can be found HERE or by calling (801) 975-4838.

Our statewide tollfree line is 1-888-999-4019 (early morning, option 8).

For our classic text advisory click HERE.

If you’re getting out and see anything we should know about please let us know.  You can leave 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 Wednesday morning.