Avalanche Advisory
Advisory: Salt Lake Area Mountains Issued by Drew Hardesty for Friday - January 31, 2014 - 5:49am
bottom line

An overall MODERATE danger exists in the backcountry today. Human triggered slides up to 12-18" deep are possible on steep northwest to north to southeast facing slopes above about 8500'...and may be triggered at a distance. Below 8500' - and more pronounced on the west to north to east facing slopes, it'll be possible to gouge down into the rain-soaked wet snow.

I wouldn't be surprised to see a close call today. Manage your terrain well - keep sight of your partners, move through suspect terrain one-at-a-time, have good communication.

Excellent safe, primo riding can be found above 9000' on slopes of 25 degrees to approaching 35 degrees in steepness. Slope angle is key.




current conditions

Let's get right to the chase - skiing and riding conditions are vastly improved. Very much so. Currently skies are clear to partly cloudy, winds are generally light from the northwest, temps are in the single digits to mid teens. Did I mention that the skiing and riding conditions have improved? Much is because the initial wave of snow Wednesday came in with densities in the mid to high teens to smooth out the old ruts, tracks, and coral from before...then slowly "dried out" - what we call a 'right-side-up' storm. (The fine print: It should be noted that an initially high rain/snow line Wednesday (varied, but some reports to 9800') has left a rain crust at ~8500-9000' and saturated much of the lower elevation snowpack.)

First the numbers - (snow/water)

  • Ogden mountains - 12"/1.68"
  • Park City mountains and Big Cottonwood Canyon - 7-10"/1"
  • Little Cottonwood - 15"/1.70"
  • Provo mountains - 9"/1.43"
recent activity

Mountain resorts reported widespread activity within the new snow with sensitive soft slabs generally 12-18" deep that would move easily with provocation.

Two avalanches reported from the backcountry that will serve as cautionary tales for today - (links take you to the Steve Achelis Wasatch Backcountry Skiing map)

  • Days Fork of BCC - Hall of the Giants - 9300' East facing - skier triggered slide on a steep breakover 12" deep and 30' wide, running 100'...failing at and below 13 January rime crust
  • Park City ridgeline No Name - 9200' Northeast facing - skier triggered slide 12" deep and 80' wide, running 700', stepping into faceted snow beneath the 13 January rime crust...and gouging into some of the weakest faceted snow money can buy...leaving a decent debris pile.
  • Brighton periphery - Clayton Peak - 10,600' East northeast facing - little info on this one but looks similar to the ones below -

Photos (left to right) - Nalli-Days, White-No Name...bottom - White - No Name

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

These storm slabs and wind slabs I'll now call Persistent Slabs - as I suspect the warmer temps and time will have settled out much of the storm instabilities. Our problems arise as - among myriad other snow surfaces - the 8-12" fell on variations of facets and rime crusts from the last couple of weeks. They'll be pockety, but found predominantly on northwest through east facing slopes above about 9000'. They may be even more localized to mid-elevation/mid-slope terrain - areas that harbored more of the weaker snow surfaces prior to the event.

A couple words of caution -

  • In shallow snowpack areas, any of these slides may then potentially step down or gouge into older, weaker snow from early winter
  • Any of these slides triggered at the 8-9000' level may gouge into wet, saturated snow from Wednesday night's high elevation rain event.

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

A damp and - at places - saturated snowpack present on west to north to east facing slopes up to - conservatively 8500' may be prone to coming unglued - in wet loose/sluff fashion - with human provocation. If you're finding the pack nearly unsupportable, look for lower angle terrain and avoid the steep terrain traps that'll dump you into a creekbed or narrow-walled gulley. Remember this sort of debris is dense, setting up like concrete.

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

Isolated pockets of healing wind slab may be found along the higher elevations. Particulary on the southerly aspects, they should respond well to ski and slope cuts or a cornice drop; test slopes well representative on these aspects. They should heal soon, but those heading to very steep exposed terrain should be aware that a few wind pockets exist and should be managed carefully, particularly above "no-fall" terrain.

weather

Clouds should fill back in and we may even see a flake or three by the afternoon as a moist unstable - yet generally light - northwest flow kicks in overhead. Winds will be generally less than 15mph from the northwest; temps will continue dropping from the low teens to the mid single digits overnight and into tomorrow. We'll see periods of light snow over the next 7 days.

general announcements

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.

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 (801-223-4150)

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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.uned.

Wasatch Powderbird Guides Blog/Itinerary for the Day.  

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

Ski Utah mobile snow updates

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.

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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 exist.