Provo Avalanche Advisory

Forecaster: Drew Hardesty

AVALANCHE WATCH »

The risk of an avalanche is expected to increase significantly but the timing and location are still uncertain. Stay tuned for updates.
Notice:

THIS AVALANCHE WATCH IS FOR THE MOUNTAINS OF NORTHERN AND CENTRAL UTAH, TO INCLUDE THE BEAR RIVER RANGE AND THE UINTAS. EXPECTEDHEAVY SNOW AND WINDS FROM CHRISTMAS EVE THROUGH CHRISTMAS WILL OVERLOAD AN UNUSUALLY WEAK SNOWPACK, PRODUCING LARGE NATURAL ANDHUMAN TRIGGERED AVALANCHES. BACKCOUNTRY TRAVEL IS NOT RECOMMENDED.THIS WATCH DOES NOT INCLUDE SKI AREAS OR HIGHWAYS WHERE AVALANCHECONTROL IS NORMALLY DONE.


BOTTOM LINE

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


Danger Rose Tutorial

The danger remains HIGH in the mid and upper elevations on slopes steeper than 35 degrees. Human triggered avalanches are a certainty. Naturals are still possible. Avoid runout zones. Those without years of experience should avoid the backcountry and stick to the ski areas. The danger may rise to EXTREME by Christmas day.

Please help us spread the word. 


CURRENT CONDITIONS

Calling it a 'moist northwest flow' would be an understatement. By the time it stopped snowing last night, most areas picked up another foot of 4-5% snow....pushing storm totals to 18-24” in the Cottonwoods and the Provo and Park City mountains. In the Ogden mountains from 8am-3pm alone, it snowed 17” of 3-4% fluff, as they raked in 37” over two days. Feast or famine, it seems. Well, get ready to belly up for the main course. A powerful Pacific storm arriving tonight is likely to bring an additional 2-3' of snow to the high country by late Friday. Temps are again in the single digits and winds have shifted to the southwest, blowing 15-20mph.


RECENT ACTIVITY

Haven't heard of much recent activity by the backcountry community in Provo.  To the north, we have the following.  The Provo mountains have a somewhat similar snowpack as the Salt Lake mountains.

Where to begin? Large natural avalanches ripped out in McDonald Draw along the Park City ridgeline, North Willow in Big Cottonwood 2-3' deep and 1000' wide, and in Yellowjacket above Mill Creek. Backcountry skiers remotely triggered large and dangerous avalanches, with some close calls. On a normal day, any of these would be headline news, but we have three. A skier 2/3 the way down the Reynold's shoulder bowl (in mid-BCC) collapsed the slope and outran the thing as it ripped out way above him. This slide then sympathetically released the main bowl wall to wall 2-5' deep, which then released the north wall 2' deep and 200' wide. Some places stepped to the ground. These are east to north aspects at 9400'. Just down the street in Butler Fork, a skier remotley triggered a 3' deep pocket 40' wide, running 200'. This was on a 40 degree northwest facing slope at 7900'. Heading back up canyon in Hidden Canyon, a skier remotely triggered a monster 3-5' deep and 150' wide there on a steep northwest facing slope at 9400'.


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

If not but for the grace of God go thee. I am convinced that remotely triggered slides have and will continue to save lives. It has saved my own. The collapsing of (an often 'persistent') weak layer, below the slab sends a 'shock wave' through the slab whereupon it releases on the nearby steep slope. You can frequently do this from the flats, valley bottoms, ridgelines, or lower on the slope where perhaps the slab is thinner (exhibit A: the Reynolds Peak slides).

The west, and north through southeasterly facing slopes have been getting the action, but the southerly aspects too have areas of weak snow. I expect that this storm will produce widespread large naturals that run to the ground on a variety of aspects and elevations. Ridgelines and drainage bottoms well away from runout potential are the keys to success. Most should hedge their bets and stay at the ski areas or enjoy the holidays in the valley.


THREAT #2

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

The second avalanche problem is the lingering instability from yesterday snow and wind.  Overnight naturals are clear indications of this issue.


MOUNTAIN WEATHER

This'll be our calm before the storm. Skies are partly cloudy this morning and winds are on prety good behavior, blowing 15-20mph. Temps are in the single digits, but should warm some during the day. We'll start to see stronger southwesterly winds by late afternoon, driving into the 40's and 50's tonight. Snowfall, beginning tonight, will favor the Ogden and Provo mountains through Christmas afternoon, when the cold front arrives. We may see storm totals of 2-3', with a good chance for lake enhanced snowfall through Friday. A moist west to northwest flow persists through the weekend and into next week, though it looks like the bulk of it will pass to the north.


GENERAL ANNOUNCEMENTS

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

The Wasatch Powderbird Guides - for information, call them at 801-742-2800 or go to their daily blog

UDOT highway avalanche control work info can be found by calling (801) 975-4838. Our statewide toll free line is 1-888-999-4019 (early morning, option 8).

The UAC depends on contributions from users like you to support our work.  To find out more about how you can support our efforts to continue providing the avalanche forecasting and education that you expect please visit our Friends page.

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 uac@utahavalanchecenter.org. (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  will update this forecast by 7:30 on Thursday morning.


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.