Salt Lake Avalanche Advisory

Forecaster: Drew Hardesty

BOTTOM LINE

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


Danger Rose Tutorial

We have a MODERATE (L2) danger for new and old hard wind slabs at the mid and upper elevations. They’re most pronounced on steep north to east facing terrain, but the gusty winds have scattered them all over the map. They’re not limited to the typical upper elevation starting zones – so treat and evaluate each slope individually and carefully in the backcountry today.


CURRENT CONDITIONS

Winds again make the headlines. The southwesterlies picked up mid-morning yesterday, blowing 30-40mph along the high ridgelines with gusts into the 50s and 60s. They remain strong. Even the more sheltered anemometers suffer gusts into the 30s. Skies are overcast and temperatures are in the mid 20s at 10,000’ and near 30 at 8000’. Riding conditions are fair in the sheltered terrain and certainly wind affected in the open bowls and above treeline.


RECENT ACTIVITY

The wind transport led to the development of soft and hard wind drifts up high and in the mid-elevations. We were able to crack out some shallow hard slabs on some steep convex test slopes in mid-White Pine of LCC. Ski area control teams reported stiff and stubborn hard drifts up to a foot deep – and we heard about one skier getting caught and carried in a shallow 6” deep and 25’ wide wind slab he triggered while descending a steep chute in mid-Days Fork of Big Cottonwood Canyon. This was on a steep east facing slope at roughly 9900’.

Ian Havlick and I checked out Wednesday night’s cornice-triggered large natural deep slab release in upper White Pine – just adjacent to White Baldy. It was enormous. Dimensions were 6-8’ deep and 300’ wide – and there was a good portion up to 12’ deep. More details can be found here.


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

Many stiff and stubborn hard wind drifts will be found on a variety of aspects and elevations today. The gusty winds allowed for plenty of wind damage and loading well off the ridgelines – you’ll still find them below steep convexities, rollovers, and cross-loaded in chutes and gulley sidewalls. The tricky part, of course, is that you may be able to ride over many hard wind lenses, gain confidence on the stability, and then find another that shatters that confidence. Tricky is the key word here – the slab is strong – allowing you to get way out onto the lens before it breaks above you. And it may not pull out on the first or second person on the slope. Look for and avoid the smooth, rounded lenses of snow. Even the shallow hard wind slabs can have nasty consequences if you’re above unforgiving terrain.


THREAT #2

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

Cornices are massive these days and are breaking off with little prodding. The winds alone are enough to tip the scales for these monsters. They may break off on approach and trigger wind slabs or potentially deep slabs below. I feel that they’re almost too large and dangerous to be dropping intentionally.


THREAT #3

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

Miscellaneous Department:

Ah yes, the low probability – high consequence – difficult to forecast for department. A couple glide avalanches were reported in Broads and Stairs Gulch of BCC during the warm up over the last week. True, it’s not as warm as it was then, but free water percolating down 5-7’ deep on the steep rocky slabs can take their sweet time and release at any time.

We’d be remiss in not mentioning the outlier Deep Slab problem. These are found in the mid and upper elevation north to east facing slopes. The last few have been triggered from above by massive cornice fall onto unsupported slopes below, averaging 5-7’ deep and a few hundred feet wide. Strong winds are no doubt contributing to cornice fall as we speak…


MOUNTAIN WEATHER

The dominant weather feature is a large Pacific storm currently spinning off the Washington coast. It’ll keep us under a strong southerly flow this morning with overcast skies. Temperatures will be in the mid to upper 20s at 10,000’ and the mid to upper 30s at 8000’. Winds will continue to blow 30-40mph or more today before a weak system ripples through this afternoon into the evening. It may be good for a few inches of snow in areas favored by a southwest flow. The next system moves through on Monday. The weather looks unsettled through the week.


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)

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.

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.

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

UDOT canyon closures UDOT at (801) 975-4838

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.

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.