Avalanche Advisory
Advisory: Salt Lake Area Mountains Issued by Drew Hardesty for Saturday - December 28, 2013 - 6:02am
bottom line

Pockets of CONSIDERABLE danger exist above about 8500' in steep westerly to northerly to easterly facing terrain. Human triggered slides up to 1-3'+ are likely and may be triggered at a distance. Dangerous conditions exist - and we'll continue the Special Avalanche Bulletin. Watch for some shallow wind slab development in the highest terrain as the winds bump with the passing "storm". Safe and excellent riding can be found on slopes less steep than about 35 degrees and not locally connected to steeper terrain above or adjacent to you.

(Disregard the yellow pocket on high elevation due south)
special avalanche bulletin

THIS SPECIAL AVALANCHE ADVISORY IS FOR THE MOUNTAINS OF NORTHERN UTAH TO INCLUDE THE WESTERN UINTAS. DANGEROUS AVALANCHE CONDITIONS EXIST IN THE STEEP WEST TO NORTH TO EAST FACING TERRAIN. HUMAN TRIGGERED AVALANCHES 1-3 FEET DEEP ARE LIKELY. THIS SPECIAL AVALANCHE ADVISORY WILL CONTINUE THROUGH THE WEEKEND.
current conditions

Skies are mostly cloudy as a weak splitting storm system passes by to the north. Our friends in Logan may see a snowflake or two, but we'll see just a bump in winds and a drop in temps. Unseasonably warm temps made the headlines yesterday with a couple mountain weather stations hitting highs approaching 50 degrees. Winds remain light except for the 11,000' ridgelines where the anemometers spin at 20mph with gusts near 30. Riding conditions remain quite good in the shady sheltered terrain. Sunlight aspects will harbor breakable melt freeze crusts with variable rime crusts generally a cm or two beneath the surface.

recent activity

We had no reports of avalanches in the backcountry yesterday. Having said that, Kobernik reported hearing the loudest collapse of the season in Porter Fork of Mill Creek while Meisenheimer found alarming results with an instructive video of his PST (propagation saw test). Resort avalanche reduction work with explosives continues to pull out slides into old snow; recently slides 2' deep on west facing terrain in Little Cottonwood.

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

Buried weak faceted snow 2-4' deep from November abounds and has been the player in many of the avalanches on west to north to east facing terrain. The most recent storm in the days leading up to Christmas was enough to quickly tip the scales in many areas, but note how the curve below is not symmetrical - in other words - with these persistent weak layers, the instability can come on quickly with the storm....but doesn't fade away just as quickly.

To overplay the Russian Roulette analogy, where there were 4 bullets in the chamber, now there are two. The consequences remain the same, just the odds of triggering it are a touch lower. 5 star observer Mark White put it well, "Finding good and safe skiing is really a thinking mans game this year."...and he's right. What to do?

  • Don't follow the recipe. The recipe for the slab avalanche is strong over weak, slab over facets. The facets are everywhere - just look and be absolutely sure - there isn't a slab. In some terrain, the pre-Christmas storm wasn't enough to create a slab over the old sugar snow. Warning! This takes loads of work to determine but it can be done.
  • Meadow Skip. Choose slopes less steep than about 35 degrees not locally connected below or adjacent to steeper terrain. Why? Persistent slabs can be triggered low on the slope, pulling the whole mess down on top of you. Hard slabs can initiate on steeper terrain and wrap around into lower angle terrain, pulling you along for the ride. No good.
  • Avoid the dragon's den altogether - choose aspects and/or elevations that don't host the dragon. There's an old saying in the business that of the Avalanche Triangle variables (snowpack, weather, terrain, people), the only one you can control is terrain. It's not true. Simply put, you can choose your snowpack and weather with your terrain choices. Considerable hazard? It's not considerable on all aspects and elevations.
Avalanche Problem 3
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 24 hours
description

That guy in the little icon with all his gear? I suspect there's a Considerable human factor danger out there. The mousetrap is set, just needs some powder starved triggers. It's the weekend after Christmas and we have 3 star (this is the Wasatch - it ain't 5 star, but it's good) skiing and riding conditions in the backcountry.

Have you ever made a mistake? Do you ever wish you could push rewind and get a re-do? Kevin Grove, professor and avalanche educator discusses a large avalanche he was caught in not long ago. "When we got to the top, I didn't stop to think, I just jumped in." Laurence Gonzales, the author of both Deep Survival and Everyday Survival, well conveys why and how smart people do stupid things. They're worth a read.

One other point about vulnerability. This idea conveys how well we'll survive an avalanche. Choosing the right rescue gear/partners and terrain with less harsh consequences helps your survival rate. But just like airbags in the automobile, airbags don't make driving safer, they make crashing safer.

weather

We'll have partly to mostly cloudy skies with the passing "storm" to the north. Temps will dip to the low 20s enroute the mid teens tomorrow. Winds will increase along the ridgelines to 20-25mph from the northwest. Another brushby follows for Mon/Tues with the ridge rebuilding for later week. Models suggest a pattern change about 8-10 days out.
general announcements

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.

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), Canyons Resort Dispatch (435-615-3322)

Snowbasin Resort Dispatch (801-620-1017), Powder Mountain Dispatch (801-745-3772 x 123).

Sundance Dispatch (801-231-4150)

DAWN PATROL Hotline updated daily by 5-530am - 888-999-4019 option 8.

Twitter Updates for your mobile phone - DETAILS

UDOT canyon closures:  LINK TO UDOT

Utah Avalanche Center mobile app - Get your advisory on your iPhone along with great navigation and rescue tools.

We'll soon be lining up a new automated emailed advisory delivery system - stay tuned.

Wasatch Powderbird Guides Blog/Itinerary for the Day.  They'll be up and running later this winter -

Lost or Found something in the backcountry? - http://nolofo.com/

Discount lift tickets are now available at Backcountry.com - Thanks to Ski Utah and the Utah Resorts.  All proceeds go towards paying for Utah Avalanche Center avalanche and mountain weather advisories.

To those skinning uphill at resorts:  it is your responsibility to know the resort policy on uphill travel.  Some allow uphill travel and have guidelines, some don't. Contact the Ski Patrol at each resort for details. IMPORTANT: Before skinning at a resort under new snow conditions, check in with Ski Patrol.  Resorts can restrict or cut off access if incompatible with control and grooming operations.

Benefit the Utah Avalanche Center when you shop from Backcountry.com or REI:  Click this link for Backcountry.com or this link to REI, shop, and they will donate a percent of your purchase price to the UAC.  Both offer free shipping (with some conditions) so this costs you nothing!

Benefit the Utah Avalanche Center when you buy or sell on ebay - set the Utah Avalanche Center as a favorite non-profit in your ebay account here and click on ebay gives when you buy or sell.  You can choose to have your seller fees donated to the UAC, which doesn't cost you a penny.

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 snow and avalanche conditions. You can also call us at 801-524-5304 or 800-662-4140, email by clicking HERE, or include #utavy in your tweet or Instagram.

The Utah Avalanche Center along with the Montana State University Ski Tracks project combines GPS technology with detailed logbook surveys completed by participants to help us understand how and why decisions are made in the winter backcountry. Participants will use a free smartphone app to record and send us their ski routes then, they will complete a simple online survey telling us some of the features of their tour. For more information visit: www.montana.edu/snowscience/tracks