Uintas Avalanche Advisory

Forecaster: Craig Gordon

SPECIAL ANNOUNCEMENT

An AVALANCHE WARNING is in effect for the western Uinta Mountains. Strong winds and expected heavy snow will overload an extremely weak snowpack. A HIGH avalanche danger exists on all steep mid and upper elevation slopes. Both human triggered and natural avalanches are likely. Backcountry travel is not recommended.


BOTTOM LINE

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


Danger Rose Tutorial

 

At and above treeline the avalanche danger remains HIGH today on all slopes approaching 35 degrees in steepness, especially those with recent deposits of wind drifted snow. Human triggered avalanches are likely. Today’s avalanches will break into weak layers of snow near the ground, creating a large, dangerous and possibly unsurvivable slide.

At mid elevations the avalanche danger is CONSIDERABLE on steep wind drifted slopes and human triggered avalanches are probable.

Remember- even if you're traveling on relatively flat terrain, be aware of steep slopes above and adjacent to you and avoid avalanche runout zones.


CURRENT CONDITIONS

 

 

Merry Christmas! While we were all asleep, a major winter storm began bearing down on the state. South and southwest winds started howling along the ridges around midnight, averaging 25 mph with gusts in the low 50’s.  Across the high peaks it’s raging with gusts in the 70’s. Four inches of new snow fell early this morning at the upper elevations with half that amount down at the trailheads. Currently it’s 17 degrees at 8,000’ and 10 degrees at 10,000’.

 

 


RECENT ACTIVITY

 

 

The region went through an active avalanche cycle Sunday, Monday and again yesterday. Very large natural avalanches along with snowcat, remotely triggered, explosives triggered (photo one, photo two) avalanches have been reported. Averaging 3’-4’ deep, all the slides are breaking on or just below the Thanksgiving rain crust near the ground and are up to 400’ wide. In addition, avalanches are breaking out along ridgelines in relatively flat terrain.

Thanks everyone for all the awesome observations this week! I especially want to thank Ted Scroggin and the staff at Park City Powder Cats for their professional dialog, advice and insight during this challenging avalanche cycle. Check out more photos here.


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

 

 

Unfortunately I’ve got bad news to share this morning.  I’m very saddened to report an avalanche accident which resulted in the loss of two lives yesterday near Logan Peak in the Rodeo Grounds. Details are still being sifted through and we will have a report posted soon. What I do know is two snowmobilers were buried for a period of time and recovered with beacons by members of their own party.

Closer to home it’s every bit as dangerous and we've got a peculiar snowpack.  Here’s what’s going on. Very weak faceted snow near the ground is something we’re used to dealing with in the western Uinta Mountains… heck it’s what we’re famous for. However this year the snowpack is far more complex. Not only do we have our usual rotten facets to contend with, nature threw in a wild card this year just to keep us on our toes. Rain crusts, like the one formed on Thanksgiving, are unusual for our neck of the woods and it’s something we’re not used to seeing. Remember- unusual weather makes for unusual avalanches. The rain crust acts like a supportable layer, giving the snowpack some strength, allowing a slab to develop on top of the weak junk show below. The snowpack feels like it has some body and structure and that’s just the problem. The deceptive curve ball is there’s no strength underneath.

I know we’ve been powder starved this year and the riding is just starting to get good, but for the next few days you’ll need to think about the consequences of your terrain choices. It’s extremely deceptive out there and avalanches triggered today are certain to be large, dangerous and unsurvivable.


THREAT #2

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

 

Winds have been active for several days, creating fresh drifts along the leeward side of ridges at the mid and upper elevations and these are sensitive to the weight of a rider. Once triggered, these manageably sized slabs can quickly get out of hand initiating a much larger, wider and more dangerous avalanche than you bargained for.  

 


MOUNTAIN WEATHER

 

 

 

A strong winter storm remains on track for the region today. We should do fairly well with the prefrontal moisture on a southwest flow and snow totals will stack up quickly this morning. I’d expect to see a foot by early afternoon. Another 8”-10” is possible overnight. Southwest winds will rage for most of the day averaging 30-50 mph with gusts in the 80’s along the high exposed ridgelines. Late this afternoon the cold air arrives, winds switch to the northwest and we should see a period of pretty intense snowfall. High temperatures today will be in the mid 20’s at 8,000’ and upper teens at 10,000’. Overnight lows will be near zero. Scattered snow showers are expected on Friday and Saturday.

 

 

 


GENERAL ANNOUNCEMENTS

Remember- your observations help to save other riders lives. So if you see or trigger any avalanches please let me know what your seeing. You can reach me at 801-231-2170 or craig@utahavalanchecenter.org

While it's quiet, now is a great time to schedule a free avalanche awareness class for your group or club. You can reach me at 801-231-2170 or craig@utahavalanchecenter.org for more details.

The information in this advisory expires 24 hours after the date and time posted. I'll update this advisory by 7:00 am on Friday Dec. 26, 2008.


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.