Salt Lake Avalanche Advisory

Forecaster: Bruce Tremper

BOTTOM LINE

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


Danger Rose Tutorial

Terrain I would continue to avoid: Slopes steeper than about 30 degrees on west, northwest, north, northeast and east facing slopes above about 8,500'

Usually safe terrain: South facing slopes and all terrain less than 30 degrees not locally connected to steeper terrain especially from below.

In general, there is a Moderate danger with pockets of Considerable danger on the slopes mentioned above.

CURRENT CONDITIONS

With just an inch or two of new snow from yesterday, a stratus layer of clouds above 9,000' continues to rime the upper mountains making the trees look like the background photo of our website (photographers take note). Temperatures are near 20 degrees with light winds from the northwest.

Riding conditions remain quite good on the wind and sun sheltered slopes with about 8 inches of soft snow on a supportable surface.

RECENT ACTIVITY

There was no new avalanche activity reported from the backcountry yesterday.

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

Yep, there's still monsters in the basement, which keep us awake at night. Here's a quick video explaining the basic setup. The snowpack is much thinner than normal with most of northern Utah 50-75 percent of normal.

The green line is this year, the red line is last year the blue line is average. What a difference a year makes.

Thin snow means weak snow and we have a layer of weak, faceted snow at the base of our snowpack with extremely variable layers above it. This means that there remain areas of buried booby traps that can be triggered by the weight of a person or snowmobile. It's a low probability - high consequence situation, meaning that they are difficult to trigger, but if you do, it will be a very large, unsurvivable avalanche (see below).

This problem exists mostly on the slopes facing the north half of the compass as well as east facing slopes but look at the danger rose for details by aspect and elevation. Most of the smart folks choose to just stay on slopes less than about 30 degrees on these slopes. If you must get onto steeper terrain, do it at a resort or on a south facing slope.

We are in the "scary avalanches" section of the probability-consequence graph.

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

The little bit of new snow buried a layer of surface hoar on many slopes, so any slab on top of that thin, weak layer will likely pop out easier than you expect. I don't think this is a much of a problem until we get more of a load on it, but it's something to watch today and especially after we get more snow by Sunday. See a good observation from Greg Gagne.

MOUNTAIN WEATHER

We'll see a day starting out much like yesterday with stratus clouds around 9,000 - 10,000', which will give us some beautiful rime on the trees and the snow surface. These clouds should dissipate by noon and we should break into a pretty, darn, nice day. Ridge top winds should be 10-15 from the northwest and temperatures should rise into the upper 20's today.

Saturday, we should have increasing high and mid level clouds in advance of a weak storm on Saturday night into Sunday morning, which should bring us about 2-4 inches of additional snow. Then, we have continued, unsettled weather with occasional snow for the next several days.

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.

Twitter Updates for your mobile phone http://utahavalanchecenter.org/twitter)

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

Wasatch Powderbird Guides does daily updates about where they'll be operating on this blog http://powderbird.blogspot.com/ .

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.

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.