Avalanche Advisory
Advisory: Uintas Area Mountains Issued by Craig Gordon for Saturday - March 24, 2018 - 3:27am
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HEADS UP-

MAKE NO MISTAKE... THE AVALANCHE DANGER IS OUT OF THE ORDINARY FOR THIS LATE IN THE SEASON. BREAKING DEEP AND WIDE AND GENERATING HUGE AMOUNTS OF BODY BREAKING DEBRIS, THESE ARE THE TYPE OF AVALANCHES THAT KILL MOST SLEDDERS.

A CONSIDERABLE avalanche danger exists in upper elevation terrain, particularly in the wind zone, above treeline. Human triggered dry snow avalanches are LIKELY on all steep wind drifted slopes, especially those facing the north half of the compass, and particularly those with an easterly component to their aspect.

At mid elevations, the avalanche danger is MODERATE. Human triggered avalanches are POSSIBLE on steep wind drifted slopes.

LOW avalanche danger is found on most south facing terrain and wind sheltered slopes.
special announcement

We couldn't get out on the snow without the great support from Polaris, Ski Doo, and Arctic Cat as well as KTM and Timbersled. Our local dealers make it happen. Tri-City Performance, Weller Recreation, Northstar's Ultimate Outdoors, Big Pine and Morgan Valley Polaris. We use these machines to monitor the snowpack across the state of Utah. We also use these machines to teach life-saving classes.
current conditions

Friday mornings storm delivered 3"-5" of heavy, dense snow across the range... which sounds resonable until we crunch the numbers. In that 3"-5" of very dense snow, we accumulated nearly an inch of water which equates to snowfall nearly three times heavier than our average density snow... yikes! In the wake of the big storm, clouds blew out of the region late yesterday and skies remained clear overnight, allowing temperatures to dip into the teens. As the next storm approaches, south and southeast winds are already on the rise, blowing in the 30's with gusts near 50 mph along the high ridges. Riding and turning conditions are soft and creamy in mid and upper elevation wind sheltered terrain.

Above are 24 hour temperatures and snow depth near Trial Lake along with winds and temperatures from Windy Peak. More remote Uinta weather stations are found here

A great body of recent trip reports, observations, and snow data here.

recent activity


Yesterday in Upper Moffit Basin, Dave and Jason triggered this, tree snapping monster. I'll let them describe-

"Large slide triggered by kicking a large cornice. Cornice triggered a wind slab when it hit the slope below, which then triggered a persistent slab in an area that had previously slide. Slide then propagated out across the slope. Total width ended up being approximately 800 feet wide, with an average crown depth of 4 feet. Ran approximately 500 vertical, taking out several trees on the way. This is an area that had shown a relatively strong, but highly variable snowpack. Up to this point, there has not been a connected slab. However, warming and wind loading created a more connected slab."

More details along with a full list of recent avalanches is found here.
Avalanche Problem 1
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 24 hours
description

Winds are cranking and now they have some snow to work with. As the next shot of snow develops later today and drifting becomes more widespread, I suspect slabs will continue to grow on the leeward side of upper elevation ridges. In addition, there's cross-loaded pockets around terrain features like chutes and gullies. In any case, today you'll want to look for and avoid fat, rounded pieces of snow, especially if they sound and feel hollow like a drum. Todays wind slabs are gonna be connected and once triggered have the potential to break deeper and wider than you might expect.
Avalanche Problem 2
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 24 hours
description

Here's what I know about the persistent weakness issue in our snowpack.

First- every significant storm that's rolled through the region this season has reactivated our dormant weak layers, especially where the pack remains thin and weak. I think of terrain that has either avalanched this winter or zones that are shallow like the south half of the range from about Soapstone to the Daniels/Strawberry area.

Second- not every steep slope we ride is gonna avalanche and that gives us a false sense of snow stability.

Third and most important- slopes with these characteristics may be reactive to our additional weight and have the possibility to break deeper and wider than you might expect.

It's a lot to digest, but when I'm uncertain about sketchy avalanche dragons, I simply avoid where they live. Steep, mid and upper elevation terrain facing the north half of the compass are prime suspects as are slopes that already avalanched this season. So here's the exit strategy... if you're looking for soft snow and safe riding, simply tone down your slope angles and avoid terrain with steep slopes hanging above you.



The natural slide in the images above is similar to what Dave and Jason triggered yesterday. This extremely connected piece of snow broke to the dirt early Friday morning and stacked up a huge piles of body snapping debris... unsurviveable if you were on the receiving end.
weather

We're in-between storms this morning and we can expect partly cloudy skies with a chance of afternoon snow showers. High temperatures reach into the 30's with overnight lows in the teens. Southerly winds are gonna be a nuisance, blowing to 50 mph along the high ridges. Snow develops on Sunday and lingers into Monday afternoon. Storm totals are encouraging with a foot of snow possible by late Monday.
general announcements

The information in this advisory expires 24 hours after the date and time posted, but will be updated by 7:00 AM Sunday March 25th, 2018.

If you're getting out and about, please let me know what you're seeing especially if you see or trigger and avalanche. I can be reached at craig@utahavalanchecenter.org or 801-231-2170

It's also a good time to set up one of our very popular avalanche awareness classes. Reach out to me and I'll make it happen.

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.