Provo 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. Pockets of CONSIDERABLE – read Pockets of LANDMINES. Dangerous avalanche conditions exist. Many, many old-timers and scarred veterans refuse to get on slopes much steeper than 30 degrees. Human triggered slides may still be triggered remotely from below. A MODERATE DANGER exists for human triggered new wind slabs up to a foot or so deep in steep drifted terrain on many aspects.

CURRENT CONDITIONS

Under clear skies, temps are in the mid teens. East to southeasterly winds continue to dominate the ridgelines, blowing 30-35mph with gusts to 45. More protected anemometers still register speeds of 20-25mph. It’s hard to complain about Wednesday night’s 3-5” whitewash…until you look east. Colorado’s front range picked up 2’+ from this last storm and we were left holding the bag.

Larry Dunn, keen backcountry skier and head of the SLC office of the National Weather Service used to live in Boulder Colorado. He likes to say that the best and fastest route to good powder there was to drive EAST, hop on a plane at then Stapleton airport and land at SLC International. Today might be the exception. Ski Eldora, anyone?

RECENT ACTIVITY

We didn’t hear about any new avalanches into the old snow yesterday, though parties experienced collapsing in both the flats of Days Fork as well as along one of its sub-ridges. We haven’t had any reports of deep slab releases since last Sunday. Minor sluffing and shallow wind slab were the only reports of action.

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

Warning! (Obscure references and philosophical ramblings in the 2nd paragraph below. ) The best and simplest came from arguably greatest guy in the world and pretty good skier Spencer Wheatley from the Wasatch Powderbird Guides – “It feels pretty good under foot until you pull out your shovel.” It’s the nightmare in the basement.

There is a term that you may be familiar with called Non-Event Feedback. It’s a cause and effect scenario where there’s plenty of cause, just no effect. Let me explain: you do your homework, dig a few holes in the snow to determine stability and get no results. You found no collapsing or cracking on the way. You ride the line. No avalanche. Therefore… the snow is stable? Not so fast. It’s more complicated than that – and it may be that you just got away with something. This leads us on to the Latin term Post Hoc Ergo Propter Hoc – “after this, therefore because of this”. The implication is that association is not the same as causation. That it was coincidental that the avalanche did not run. There’s another name for this - Luck. Perhaps you just didn’t hit the sweet spot on the slope.

The snowpack, in meteorological terms, is – and shall remain - Conditionally Unstable. It has the potential to avalanche – it just needs a trigger at the right time, in the right spot.

Bruce put together yet another excellent tutorial on the Deep Slab Instability.

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

The moderate to strong south-easterly winds will continue to drift Wednesday night’s few inches into sensitive drifts in unusual loading patterns. Westerly aspects as well as anomalous cross-loaded gulleys will be suspect. Those on auto-pilot may get surprised today.

MOUNTAIN WEATHER

We should have mostly clear skies, temps warming to near 20 degrees at 10,000’; the upper 20s at 8000’. Easterly winds should blow 20-25mph with occasional high gusts. The next storm splits dramatically Tuesday night into Wednesday. Warming trend follows for late week.

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.