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.

keeping you on top


Thursday, December 13, 2007  7:30 am
Good morning, this is Bruce Tremper with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory.  Today is Thursday, December 13, 2007 and it’s about 7:30 am.


I will give a free avalanche awareness talk tonight for the Wasatch Mountain Club but the public is welcome.  It will be at 7:00 pm at the South Valley Unitarian Church, which is 6876 S. Highland Drive in SLC.


There will be a benefit for our partners, the Friends of the Utah Avalanche Center, tonight at Brewvies .  It will be a double feature of “Lost and Found” from TGR and “Sublimation Experiment” from KGB. Two shows, at 6:30pm and 9:00pm.  Admission: $7 pre pay / $10 at the door CLICK HERE TO BUY TICKETS 


Alta Community Enrichment will be sponsoring a free women's avalanche beacon clinic today, December 13th, from 9 am until around noon.  Meet inside the Albion Grill at Alta's Ski Lift's upper lot at 9am.  Skies, snowshoes or just boots OK.  Extra beacons available. For more information call 742-9712 OR EMAIL [email protected].


Current Conditions:

Temperatures are about 5 degrees warmer this morning than yesterday morning with ridgetop temperatures 5-10 degrees.  Ridge top winds are reasonable around 10 mph from the northwest and around 15 mph on the most exposed peaks.  You can expect increasing clouds through the day with light snow showers tonight.

Snow surface conditions are the usual mixed bag after it has not snowed in a few days.  There is sun crusted snow on the south facing slopes, some wind damage within 100 feet of the ridgetops from northeast winds a couple days ago.  But the slopes that face the north half of the compass are still quite delightful.  The biggest complaint, of course, is the shallow snowpack on all slopes except upper elevation north facing, where you hit many rocks.


Avalanche Discussion:

We did not hear about any avalanche activity yesterday from the backcountry.

The main problem is our old layer of weak, faceted snow left over from the November drought, which existed only on the slopes that face the north half of the compass above about 9,500’.  Everything else was bare ground, so when the snowstorms finally started a couple weeks ago, the new snow stuck well to everything except the aforementioned high north facing slopes, where there was widespread natural and human triggered avalanches last weekend and the weekend before.

Even though most of these slopes have slid already, there are still a few lingering slopes that you can still trigger.  For instance, one very experienced skier triggered one a couple days ago in Wilson Glade, which is a northeast facing slope near Gobbler’s Knob between 30 and 35 degrees in steepness (Link).  I suspect there are other slopes like this that are still hanging in the balance. A pattern we often see is that the slopes 35-45 degrees slide during the storm, but afterwards, a few slopes slightly less than 35 degrees still linger waiting for a trigger.  Any avalanches triggered on these slopes will be large—around 3 feet deep and quite wide.

With the recent wind and some snow, it’s getting hard to tell which slopes slid during the last storm, so you have to do some creative research and poking around to sort out the safe slopes from the unsafe ones.


Also, strong northeast winds a couple days ago created some wind slabs along the upper elevation ridges that may still be lingering.  So as usual, you should avoid any steep slopes with recent wind deposits.


Bottom Line:

The avalanche danger is MODERATE on upper elevation northwest, north and northeasterly facing slopes steeper than about 33 degrees, above about 9,000’ in the Salt Lake, Park City and Provo area mountains. On these slopes it continues to be possible for a person to trigger a dangerous slab avalanche 2-3’ deep about 100’ wide.


Throughout all the range, there is also a MODERATE avalanche danger on any steep slope with recent wind drifts, which you will find mostly along the upper elevation ridges.


Mountain Weather: 

We will have increasing clouds today in advance of a weak cold front tonight, which should bring us 2-5 inches of snow.  It will be just enough to freshen things up a little, but probably not enough to increase the avalanche danger very much.  Ridge top winds today will be west to northwest 15 mph and temperatures should be near 10 degrees.  Friday morning, ridge top temperatures will drop to just above zero and ridge top winds should not rise much above 15 mph.

We will have another, weaker, system by this weekend and the longer ranger models indicate a stronger system in about another week.

(Click HERE where you can get another look at the weather on our revamped weather page.  This page, which we update every day around noon.)



For an avalanche education class list, click HERE.  

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

The UAC has temporary job openings for doing avalanche outreach in more rural areas.
  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.

Brett Kobernik
will update this advisory by 7:30 Friday morning.