Provo Avalanche Advisory

Forecaster: Bruce Tremper

BOTTOM LINE

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


Danger Rose Tutorial

Terrain I would avoid:

* Mid and upper elevation slopes facing the north through east facing quadrants of the compass on slopes approaching 35 degrees or steeper and slopes locally connected to them.

* Any steep slope with recent wind deposits, which usually look smooth and rounded but are difficult to recognize in these conditions.

Safer terrain:

* Slopes less than 30 degrees not locally connected to steeper terrain.


CURRENT CONDITIONS

Backcountry riding conditions have been described using many unflattering terms, many of which I can't repeat here. Perhaps the best conditions you can find consist of 2 feet of bottomless depth hoar capped by a thin, breakable, rain crust with a layer of dust on top. Finally, the ferocious winds on Friday night created extremely variable, thin, hard wind slabs mixed with pine needles on top of the whole mess.

The good news is that it's warm and sunny up above the rapidly increasing valley smog.


RECENT ACTIVITY

The dragons are still cranky. Although we did not hear about any triggered avalanches from the backcountry yesterday, the resorts got several hard slabs with explosive control work. One released from a 10,600' N-NE facing slope in upper Little Cottonwood Canyon broke out 2-3' deep and 170' wide. There was another 1-2' deep, 50' wide hard slab on the Park City side of the range. Finally, Drew Hardesty was able to collapse an east-facing test slope above the town of Alta.


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

Hard slabs on very weak depth hoar were once described to me by a prominent Canadian avalanche expert, "like when your crazy aunt comes for a visit; she just stays forever and you just never know when she's going to snap."

Things are extremely tricky right now and these conditions will likely fool lots of very avy-savy people. There was very little snow to blow around when the extremely strong winds hit Friday night, so the wind slabs are thin, localized, variable, very hard and difficult to recognize using visual clues. I've talked to several avalanche experts--me included--that started out their day thinking not much was going on and finished the day thinking that things were really scary and tricky.

We have very hard, thin, wind slabs on top of extremely weak, faceted snow, which is like a thin pane of glass on top of tortilla chips. At least for me, I just don't want to mess with these conditions and avoidance is going to be my option for at least the rest of this week.

You will find these conditions mostly on mid and upper elevation, north through east facing slopes.

See my video and snowpit from yesterday.


MOUNTAIN WEATHER

Same as it ever was.... Sunny and warm up above the valley inversion. Daytime highs on the ridges will get up near 40 degrees with overnight lows around freezing. Winds will remain light and skies mostly clear.

The extended forecast calls for more of the same. We may get a slight disturbance next weekend but we don't see any snow in the forecast for the next 10 days.


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 UDOT at (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.