Salt Lake Avalanche Advisory

Forecaster: Drew Hardesty

SPECIAL ANNOUNCEMENT

MID-MORNING UPDATE:

Two sun-induced natural soft slabs released at 8am above Little Cottonwood road. Neither hit the road, but continued reports of human triggered slides in Cardiff Bowl and Two Trees (SE facing) and wet loose natural activity on Cardiac Ridge warrants an update.


BOTTOM LINE

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


Danger Rose Tutorial

It's an exceedingly complex pattern right now. Pockets of CONSIDERABLE danger exist on many slopes approaching 30 degrees and steeper. The danger of triggering a 1-2’ soft slab is most pronounced on the mid and upper elevation northwest through northeast through southeast facing slopes. Initially triggered slides may wrap in to the south or southwest as well. Low elevations cannot be completely disregarded either. Careless routefinding or disregard for the new and old instabilities will result in a burial or injuries.

CURRENT CONDITIONS

Skies are clear aloft with some residual moisture lingering in the basins and valleys. Yesterday’s wave produced a couple-few inches of thick-around-the-ankles 12% snow. Water weights across the range totaled about a half inch of snow-water-equivalent or more from Ogden to the Cottonwoods to Provo. Winds are generally light from the northwest. It’s not the hero snow we’ve had through the weekend, but at least there’s some patchy rime as a capstone.

RECENT ACTIVITY

Activity continued to be reported from across the range.

· A party skiing the Gobbler’s Knob Shoulder remotely triggered a soft slab about a foot deep and reported to be 500’ wide. It was on a northwest facing slope at around 9500.

· In the Brighton/Solitude periphery, a skier unintentionally triggered a pocket 12-18” deep and 50’ wide near Figure 8 Hill, a popular north facing slope at 9700’.

· Another report came in of an unintentionally triggered slide in Hidden Canyon up to a foot deep and 100’ wide. This on a steep northeast facing slope at 9700’.

· In the Provo mountains, one skier in the South Fork observed a new shallow natural on a steep east facing slope at 9200’, while in the north fork, a skier unintentionally triggered a slide on top of a buddy down below. The lower skier washed down the slope for 50’ and was able to grab a tree to arrest the slide.

· In the Ogden area mountains, one of our most experienced observers unintentionally triggered a soft slab a foot deep and 100’ wide on an east-northeast facing slope at 7400’. He also reported remotely triggered cracking everywhere on lower angled slopes.

THREAT #1
WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

The week-old buried surface hoar and recrystallized snow remains active and will continue to be cranky from the additional water weight from yesterday combined with today’s sun. It’s thickest and most prevalent in the mid and low elevation sheltered areas, but clearly found on the off aspects as well as the upper elevations. I’ve found it to be quite reactive in my snow analysis when not collapsing it or remotely triggering slides from an area of safety.

Remember that these surface hoar slides may pull back onto lower angled slopes and may propagate more widely now that the overlying slab has stiffened. Careful route finding remains critical. Even if you’re out of the way at the bottom, remember that remotely triggered slides may pull out the adjacent, untracked slope you’re standing under.


THREAT #2
WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

Ah yes, the nagging Deep Slab Instability. Unlikely, but still possible to trigger in thinner super-weak zones in steep rocky northerly terrain. While snowpit tests indicate slow-healing, the structure remains suspect in the repeater avalanche zones, and in the steeper terrain of Mill Creek and the Park City ridgeline. This is more prevalent in the Logan and Western Uinta mountains.

THREAT #3
WHERE PROBABILITY SIZE TREND
      Over the next 8 hours.

Direct sun and warming temperatures will continue to produce wet loose and likely wet slab avalanches today. Changing conditions warrant an update.


MOUNTAIN WEATHER

We’ll see mostly clear skies today with light northwesterly winds and temperatures warming into the low 20s at 10,000’. Increasing clouds tomorrow with a do-nothing wave of moisture, followed by a fair system for Thursday. This will likely benefit areas north of I-80. A complex pattern follows for the weekend and beyond, with some hints of a moist westerly track of storms.

GENERAL ANNOUNCEMENTS

Please contact Alta Central (801-742-2033) if you trigger a large avalanche in the backcountry, especially if you are adjacent to a ski area, 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.

Discount Lift tickets: Ski Utah, Backcountry.com, Alta, Deer Valley, Park City, The Canyons, Wolf Mountain, Snowbasin, Beaver Mountain, Brighton, Sundance, and Solitude have donated a limited number of tickets for sale at discounted prices.

Wasatch Powderbird Guides flight plan.

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

Daily observations are frequently posted by 10 pm each evening.

Free UAC iPhone app from Canyon Sports.

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

UDOT canyon closures UDOT at (801) 975-4838

We appreciate all your avalanche and snow observations. You can also call us at 801-524-5304 or 800-662-4140, or email to uac@utahavalanchecenter.org

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.

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.

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.