Salt Lake Avalanche Advisory

Forecaster: Evelyn Lees

SPECIAL ANNOUNCEMENT

The Wasatch Powder Keg race is this morning, and there will be some early morning congestion in the backcountry around Brighton, especially in the Milli Back Bowl area.


BOTTOM LINE

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


Danger Rose Tutorial

It will be a day of INCREASING avalanche danger. Strong winds ahead of the cold front and periods of heavy snowfall this afternoon will increase the avalanche danger to CONSIDERABLE on slopes steeper than about 35 degrees with fresh drifts of windblown snow. The possibility of triggering a slide on a more deeply buried weak layer or within the new snow will increase to pockets of CONSIDERABLE this afternoon as the snow piles up. Backcountry travelers should in full defensive mode today, using careful route finding up and down, good travel habits, and conservative decision making. Always have an escape plan, and constantly reevaluate today’s changing conditions.


CURRENT CONDITIONS

It is cloudy, warm and very windy this morning ahead of the cold front, scheduled to arrive around noon. Current temperature readings in the mid 20’s to low 30’s may give the impression of warmth, but combined with the southeasterly winds averaging 25 to 35 mph across the highest peaks, with gusts in the 40’s, the wind chill is in the single digits and low teens. The last remnants of powder are limited to wind sheltered, northerly facing slopes at the upper and mid elevations, amidst a sea of breakable and supportable crusts.


RECENT ACTIVITY

Yesterday, the expected wet loose sluffs occurred with daytime heating, with southeast and south facing slopes the most active. There were also wind slabs triggered on the northeast face of Little Superior and northwest side of Lewis Peak. But backcountry users need to keep in mind the bigger picture. Avalanche activity from the past week is a better indication of how complex and variable in distribution the snowpack weak layers are. A slide was triggered on a persistent weak layer in Scotties Bowl (photos later this morning), and several large naturals occurred in upper Stairs and Broads Fork.


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

This morning, sensitive new wind drifts will be the most widespread hazard. Strong winds always find snow erode, depositing drifts on a wide variety of aspects and elevations. The new drifts will be both along the ridges, and well off ridgelines, cross loaded onto mid slope breakovers and around sub ridges. As snow builds up this afternoon and the winds shift to the west and northwest, the wind drifts more widespread and sensitive.


THREAT #2

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

In any area where the new snow piles up rapidly this afternoon, sluffs and soft slabs may be triggered on steep slopes, and may run farther than expected where there are underlying slick crusts.


THREAT #3

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

While less widespread, the deepest (2 to 3 foot) and most dangerous slides a person could trigger will be those breaking on the buried weak layers of surface hoar and near surface facets. This past week’s natural and human triggered slides show that there are still areas, not necessarily predictable, where one of these deeper slides can be triggered. Slides breaking on these layers are not responsive to slope cuts, but will tend to break out above you, from a distance or on the 2nd or 3rd person. With additional loading from wind and new snow, it may become easier to trigger one of these deeper slides today, on the northwest through northeasterly facing slopes, especially in shallow snow pack or rocky areas.


MOUNTAIN WEATHER

An energetic storm system is headed our way, and the cold front should reach the northern Wasatch mountains around noon. Ahead of the front, the southerly winds will average 25 to 35 mph across the higher terrain, with gusts to 50, and scattered snow showers will occur. Isolated lightning is possible both before and with frontal passage. Behind the front, snow, heavy at times, should fall steadily until dark, with rates of 2”/hour or more possible. Snow will continue tonight, and storm totals of 7 to 12” are possible by Sunday morning, with higher amounts in areas favored by northwest flow. High pressure will build into the area late Sunday, with dry and warmer than average conditions through Wednesday. Another storm is possible late in the week


GENERAL ANNOUNCEMENTS

SLC: 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.

Ogden: Please contact Snowbasin ski patrol (801620-1000/1017) 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.

Provo: Please contact Sundance ski patrol (801 -223-4150) 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 fill out the observation form on our home page.

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.

Brett 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.