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

It’s a difficult forecast with a mostly MODERATE danger with isolated pockets of CONSIDERABLE ON many aspects at the mid and upper elevations. Dangerous human triggered avalanches remain possible. Good, low angle corn and settled powder skiing can be found on slopes less steep than 30 degrees. Really.

CURRENT CONDITIONS

Skies are clear. Under the influence of a “parent” low pressure system just off the coast of British Columbia, a weak weather disturbance triggered increased southwesterly winds yesterday (15-25mph, gusts to 40) and even put down an inch of new in the Logan area mountains overnight. Sadly, the new inch did little to affect this year’s total snow-water-equivalent as matched against the average. (Easily found here at the SLC National Weather Service utilizing the NRCS snotel weather sites, one can easily make a quick scan across the state for snow/water amounts.) The Tony Grove snotel site (in Logan) remains at 87% of normal (unverified) – which I guess is a passing grade of B. Most other sites, however, come in with a grade of C or D. We may have to take this winter all over again.

Overnight lows are in the upper 20s and low thirties. We’ll have a decent refreeze of the snow surfaces. You’ll be able to find good corn riding on the southerlies and patches of good soft recrystallized snow on the protected northerly aspects.

Also check out Doug Wewer's time lapse video from Ogden.

RECENT ACTIVITY

We heard of no new significant activity from the backcountry yesterday, though over the weekend a snowbike remotely triggered a 1.5’-2’ deep and 250’ wide avalanche on a steep southeast facing slope at 9600’ near the Ant Knolls above Midway….while wet loose rollerballs cascading over a cliffband apparently triggered a 2-4’ deep and 250’ wide hard slab on a steep northwest facing slope at 10,100’ in upper Holy Toledo (upper Cardiff Fork of BCC). A couple glide avalanches released in Broads – probably over the weekend (4-6’ deep and 100’ wide. See link below). Explosive testing in uncompacted terrain yielded no results and many continue to ride steep lines with no incident.

A quick note on route and campsite selection and a guide to avalanche runout zones. Ever wondered if you were in the runout of an avalanche path?


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

There can be a moderate danger of storm snow avalanches and a moderate danger of deep or persistent slabs. Sorta. The first is what I’d call Manageable, the 2nd, well, not so much. Unmanageable means you can’t really predict or intentionally trigger the slide. Often you trigger the thing remotely, and often pulls out above or adjacent to you. You can ride 10 slopes and trigger something on the 11th. These avalanches (see above) are not benign at all – who wants to get caught in a 2-4’ deep and 250’ wide hard slab that breaks 50’ above you? Could be curtains. It’s why I choose completely different terrain when faced with persistent slab problems vs. manageable storm snow problems.

So it comes down to Likelihood x Size x Distribution (x Confidence)

Likelihood – low to moderate, hard human triggered

Size – Size 2-3 (could injure or kill a person to could damage or bury a car)

Distribution – widespread to ubiquitous (this is the kicker – these avalanches due to the poor structure have been found all around the compass).

Confidence – moderate (which is to say – not high. See the Hoyt Peak accident video (Uintas last Sunday) with multiple tracks already on the slope)

THREAT #2
WHERE PROBABILITY SIZE TREND
      Over the next 8 hours.

Slightly cooler temps and sustained southwesterly winds should extend the window on the steep southerly aspects today. Still – if the crust has deteriorated or the snow becomes soggy and unsupportable, it’s time to change aspect or hit the road.

Be careful when approaching cornices as they will continue to get sensitive with the warming. They often will break back farther than you think they might.

MOUNTAIN WEATHER

We’ll have clear skies and moderate increasing to strong (by tonight) southwesterly winds. Temps will again rise to the mid 40s at 8000’ and near 30 at 10,000’. This will be the pattern through the week with very strong southwesterly winds on Friday preceding this weekend’s storm. Doesn’t look great at this time.

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 and Park City – 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/ .

Remember your information can save lives. If you see anything we should know about, please 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.