Salt Lake Avalanche Advisory

Forecaster: Evelyn Lees

BOTTOM LINE

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


Danger Rose Tutorial

There are pockets of CONSIDERABLE avalanche danger on any steep slope with recent drifts of windblown snow. Avoid all wind drifts on steep slopes, but especially higher elevation slopes facing northwest through northeast, where slides could break 1-2’ deep into the older snow.

Even without fresh wind drifts, there continues to be an overall MODERATE avalanche danger on steep slopes facing northeast through northwest above roughly 9500’ - where one might trigger an avalanche with serious consequences.


CURRENT CONDITIONS

It is cold and windy start to December – mid and upper elevation temperatures are in the teens to single digits and the easterly winds are blustering their way through the mountains and canyons, with 15 to 25 mph averages and gusts to 45 mph common. The strongest and most sustained winds so far have been in the Ogden area mountains, where averages 35 to 45 mph have occurred, with gusts in the 60’s.

Wind Chill is a serious issue today - it will feel like it is well below zero in exposed terrain. Estimated new snow amounts are in the trace to 2 inch range, but it’s hard to measure with the winds.


RECENT ACTIVITY

There was one report yesterday of a collapse on an upper elevation, northerly facing slope.


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

The head line winds will be moving snow today, eroding away at even the hardest surfaces of our worn out snow pack. Strong winds from an unusual direction will create drifts and isolated pockets of wind slab in unusual places. Much of the windblown snow will land on the shallow snow pack of the westerly facing slopes, but cross loading and drifting will occur on other aspects. The wind drifts will be especially sensitive and easy to trigger where they land on slopes that had loose, sugary surface snow. With these easterly canyon wind events, don’t just be looking for drifts along the higher ridge lines and in the higher terrain, but also on mid to lower elevation slopes.


THREAT #2

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

But don’t let the new kid in town – the wind drifts – distract you from the more persistent snow pack issue – the deeper weak layers of sugary snow. The additional weight from today’s wind drifts could make it more likely for a person to trigger a slide on one of the faceted weak layers, either near the ground or just below the last batch of wind slabs. Remember, with faceted weak layers, slides can be triggered from a distance, and renewed collapsing will be a warning sign of an unstable snow pack.


MOUNTAIN WEATHER

The current strong easterly wind event should continue over the area for most of the day, with the focus remaining in the Ogden area mountains. While most mountain stations will have 20 to 25 mph averages, with occasional gusts to 60 across the highest terrain, at favored exposed locations, most likely in the Ogden area mountains, wind speeds could average 35 to 45 mph for long periods of time, with gusts to 60. Temperatures will be low teens to low 20’s today, with the wind chill in the negative digits in exposed terrain. Wind speeds should decrease by Friday morning. A second, weaker storm system will drop in from the north Friday night into Saturday, bringing a reinforcing shot of cold air and a chance for minor accumulations of snow.


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

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

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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.