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

Pockets of CONSIDERABLE danger exist on the steep mid and upper elevation westerly to northerly to easterly facing slopes. It's a terrible game we play with a Low-Probability High-Consequence avalanche dragon. Best to skip this dance or stay on lower angle terrain. A localized MODERATE DANGER remains for human triggered wind slabs up to a foot or so deep in steep drifted terrain on many aspects.

CURRENT CONDITIONS

Skies are clear with overnight lows dropping into the single digits and low teens. I'll be glad to see the easterly winds move out. They've dropped overnight and most anemometers are at or less than 15mph. Riding conditions remain quite good and safe on wind protected, shady low angle slopes.

RECENT ACTIVITY

Not much good comes out of the easterly winds...it's likely they played the key role in two large natural deep slab releases in upper Mineral Fork of Big Cottonwood Canyon overnight Friday into early Saturday. These are at the head of Mineral...north to northwesterly facing slopes at roughly 10,300'. Google Earth photo below.

Elsewhere, explosive control work pulled out another deep slab in steep high northerly terrain in Little Cottonwood...and others found a smattering of soft and hard wind drifts that cracked out or ran with some provocation. These new drifts from the easterly winds were pockety and generally less than a foot deep. A snowmobiler in the Western Uintas yesterday triggered a deep slab avalanche 3' deep and 100' wide on a steep east facing slope at 9800'.

One collapse noted in the flats of previously undisturbed terrain of American Fork canyon.

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

The rating system for rock climbing offers a good example of the current snowpack situation. Climbing grades use the modifier 'X' when the route is poorly or completely unprotected. In other words, with a fall, "Serious injury or death may occur.' Avalanches, like rock routes, come in all shapes and sizes, difficulty and consequence. If you fall on a 5.9 route, and it's well protected, most likely you'll be ok. If you fall on a 5.9X route, it;s curtains. We have 5.9X conditions in the backcountry. Triggering these monster slides is becoming more difficult...but if you do "Serious injury or death may occur."

Stay tuned - next week I'll go into the archives to pull out the old fly-fishing metaphor -

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

Lingering soft and hard wind drifts from the past 48 hours sit on a variety of weak surface snow from last week's period of warm sunny days. They're scattered on a variety of aspects - even mid-slope - and should be avoided, particularly with consequential terrain below (trees, cliff bands, gulleys).

MOUNTAIN WEATHER

A weak upper Level Low pressure system will slowly give way to a short lived spell of high pressure. We'll have mostly clear skies, light to moderate easterly winds, and temps near 20 at 10,000' and the mid to upper 20s at 8000'. A sharply splitting system dives way south into Mexico Tuesday into Wednesday and we'll see little in the way of precipitation with the northern branch of the storm. Fair weather follows for the end of the week. The weather models offer little agreement for the weekend...

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

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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.