Skyline Avalanche Advisory

Forecaster: Brett Kobernik

AVALANCHE WARNING »

Dangerous avalanche conditions are occuring or are imminent. Backcountry travel in avalanche terrain is not recommended.
Notice:

An Avalanche Warning has been issued for the Western Uinta Mountains and the Wasatch Plateau Manti Skyline area.  A thin and persistently weak snowpack exists in these areas.  A good amount of water weight has been added in the form of snow and additional weight is expected over the next 36 hours.  This additional weight is enough to start producing natural avalanches and human triggered avalanches are also possible.  These avalanches have the potential to be large and dangerous.  Backcountry travel is not recommended in the higher elevations above around 8500’ especially on the northerly facing slopes.


BOTTOM LINE

Danger by aspect and elevation on slopes approaching 35° or steeper.
(click HERE for tomorrow's danger rating)


Danger Rose Tutorial

The avalanche hazard is CONSIDERABLE with pockets of HIGH throughout the range today.  Thursday’s wet heavy snow fails easily as a manageable wet slab.  However, the take-home message for today is “step down.”  If the new snow starts moving on wind sheltered shady aspects it will likely step down into the buried surface hoar layer failing as a 20" deep slab.  If this starts moving, it has the potential to trigger large, destructive & deep slab avalanches.  The snowpack needs time to adjust to this new load and big exposed pieces of terrain need a healthy amount of respect today. 


CURRENT CONDITIONS

The good news is that there's "fresh" snow in the forecast area again.  The bad news is that it's of the sierra cement variety.  About 6" of wet, heavy snow fell throughout the forecast area Thursday night.  It's been pretty warm all week, with day time highs reaching into the 40's even at ridge top.  It's official; there won't be any over the hood faceshots this weekend.


RECENT ACTIVITY

Reports of a few big avalanches slowly trickled in this week.  Some folks were high-marking on a tracked up slope in Jordan Canyon last week when one rider triggered the deep slab that haunts our dreams.  5 feet deep x 160 feet wide running 1000 feet down the slope.  The rider that triggered the slab managed to escape to the side and was unharmed.  His friends waiting at the bottom managed to get out of the way too.  This deep slab cleaned out the entire season’s snowpack and left bare ground in its wake.  This is the deep slab failing on facets at the ground that has been covered in the forecast all season. 


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

I know I sound like a broken record here, talking about the deep slab avalanche potential week after week.  But, as evidenced by the close calls this week, deep slab avalanches in the forecast area are fact, not fiction.  While the warming has helped strengthen the upper pack, the facets remain weak and intact at the ground.  Thursday's storm added a full inch of water to the mix, and the pack needs time to adjust to this new load.  A rider may be the straw that breaks the camels back.  Triggering a deep slab avalanche is a mistake that you may not live through.


THREAT #2

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

Friday's field day reminded me of my time on the coast.  The new snow is dense, wet & heavy, about 17% density to be exact.  It's also very high in traction and will allow a good rider to go almost anywhere they point the machine.  However, don't let this funky snow lure you into complacency.  It's easy to trigger a new snow avalanche out there right now.  For the most part these new snow avalanches are pretty manageable.  But remember that even a small slab can push you where you don't want to go, say over a rock band or through a stand of trees.

 

 


THREAT #3

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

To further complicate things, there is a buried surface hoar layer in shady wind protected locations. (Read: North through East facing trees.)  If you get the new snow moving in one of these locations, you'll likely get the buried surface hoar to fail too, resulting in a fast moving 20" deep slab.  Get a 20" slab moving and now there's the potential to get the entire snowpack to fail at the ground......


MOUNTAIN WEATHER

It's just below freezing this morning on the skyline with winds steady out of the W - SW.  A trace of wet heavy snow fell over night adding to the 6" of glop we received Thursday night.  Although the winds are up, the snow is so heavy that it won't be blown around.  A series of moist weak disturbances are sitting off the coast of California right now meaning that we should see more of the same into early next week. 


GENERAL ANNOUNCEMENTS

If you see or trigger an avalanche it would do the community good to report it.  Your observations help to save the lives of others.  The forecast area is large, and due to funding cuts I only have one field day to spend on the Skyline.  This means that I can't possibly see it all.  I need you to help me, help you.  Please share your observations and experiences: 

Shoot me an email: grant@utahavalanchecenter.org and or call me on my cell: 406-370-1337.  Thanks!

Due to budget cuts we are only able to produce an advisory that is updated each Saturday morning. 

Keep in mind that conditions change dramatically and that information may not be relevant for later in the week.

Want to schedule an avalanche awareness talk?  Contact me for details.


This information does not apply to developed ski areas or highways where avalanche control is normally done.  This advisory is from the U.S.D.A. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur.


This advisory provided by the USDA Forest Service, in partnership with:

The Friends of the Utah Avalanche Center, Utah Division of State Parks and Recreation, Utah Division of Emergency Management, Salt Lake County, Salt Lake Unified Fire Authority and the friends of the La Sal Avalanche Center. See our Sponsors Page for a complete list.