Provo Avalanche Advisory

Forecaster: Bruce Tremper

AVALANCHE WARNING »

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

The AVALANCHE WARNING continues for the mountains near Salt Lake, Provo, Ogden, Logan and the Western Uintas. A High avalanche danger exists for the Wasatch Range and the Uinta Mountains with an Extreme danger in the Logan and northern Ogden area mountains. Heavy, dense snow with wind has overloaded an extremely weak pre-exisiting snowpack. Many natural and human triggered avalanches have occurred and may continue today. People should stay off of, and out from underneath, any steep slope. Only those with excellent avalanche training and experience should attempt backcountry travel.


BOTTOM LINE

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


Danger Rose Tutorial

No-Go terrain: All slopes approaching 33 degrees or steeper including locally connected slopes especially from the bottom.

Safer terrain: You can find much safer terrain on slopes less than 30 degrees and not locally connected to steeper terrain.

There continues to be a High danger in the Wasatch Range and western Uinta Mountains with an Extreme danger in the Logan and Ogden area mountains.


CURRENT CONDITIONS

Snow totals are now around 18 inches in the Cottonwoods with 2.5 inches of water weight. Winds were very strong yesterday from the west. The new snow was very dense with rain falling yesterday up to around 8,000', making slabby, arduous trailbreaking. A few inches of lighter snow fell overnight.

The Logan and Ogden area mountains got the brunt of the storm so far with an incredible 6 inches of water weight on Ben Lomond Peak and 5 inches of water at Tony Grove in the Logan area mountains. This nearly doubled the snow water equivalent of their snowpack whereas the storm added a measly 20% to the Cottonwood Canyons snowpack. Central Utah got almost no snow.


RECENT ACTIVITY

Wow, a very active day. Avalanche control with explosives at resorts produced many destructive avalanches, many in unusual areas. Both natural and human triggered avalanches occurred in the backcountry, which are too numerous to mention. Check our Current Conditions section for the complete list, photos and videos. In summary, large slides on Twin Lakes Pass, Gobbler's Knob, Reynolds, much of the Park City ridgeline, plus numerous smaller slides.


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

It's pretty simple. High danger. It's like parking an Oldsmobile on top of a stack of champagne glasses. Stay off of, and out from underneath, steep slopes. The worst areas are upper and mid elevation slopes that face the north and east quadrants of the compass, especially on slopes with recent wind drifts from the strong winds from the west.

And this will last for a many days. The extremely fragile, depth hoar under all this new snow is what we call a "persistent" weak layer because it will continue to produce avalanches for many days after it's loaded with weight. As Drew said a week or two ago, "Persistent weak layers have to be matched by equally persistent patience."


MOUNTAIN WEATHER

This portion of the storm is winding down and we should see just a few light snow showers and perhaps some periods of sun this afternoon. Ridge top winds will blow 20-30 from the west and southwest with temperatures in the mid 20's.

But it ain't over yet. The final surge of this storm system will come overnight and most of Saturday with a crecendo of another foot of snow with very strong winds from the southwest and turning northwest. This last pulse will end with a cold front so it will put some welcome lighter snow on top of our dense snow. We should get another foot or more of snow starting tonight and it should snow most of Saturday.


GENERAL ANNOUNCEMENTS

If you trigger an avalanche in the backcountry - especially if you are adjacent to a ski area – please call the following teams to alert them to the slide and whether anyone is missing or not. Rescue teams can be exposed to significant hazard when responding to avalanches, and do not want to do so when unneeded. Thanks.

Salt Lake – Alta Central (801-742-2033)

Ogden – Snowbasin Patrol Dispatch (801-620-1017)

Provo – Sundance Patrol Dispatch (801-223-4150)

Dawn Patrol Forecast Hotline, updated by 05:30: 888-999-4019 option 8.

Daily observations are frequently posted by 10 pm each evening.

Subscribe to the daily avalanche advisory e-mail click HERE.

UDOT canyon closures UDOTat (801) 975-4838

Wasatch Powderbird Guides are suspending the opening of helicopter skiing operations. Once we have enough snow cover, daily updates to this blog http://powderbird.blogspot.com/ will begin for the 2011-2012 season.

You have the opportunity to participate in the creation of our own community avalanche advisory by submitting avalanche and snow observations. You can also call us at 801-524-5304 or 800-662-4140, or email by clicking HERE

Donate to your favorite non-profit –The Friends of the Utah Avalanche Center. The UAC depends on contributions from users like you to support our work.

We will update this forecast tomorrow morning. Thanks for calling.


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.