UDOT PLANNED AVALANCHE CLOSURES!!

Forecast for the Salt Lake Area Mountains

Drew Hardesty
Issued by Drew Hardesty for
Wednesday, December 17, 2014

Pockets of MODERATE avalanche danger exist for lingering wind drifts as well as loose snow/point-release avalanches. Shooting cracks on the slope from your weight will be an obvious clue of instability. It's possible that an initiated avalanche in northwest to easterly facing terrain may pull out an older wind drift sitting on faceted snow from last week.

Low
Moderate
Considerable
High
Extreme
Learn how to read the forecast here
Special Announcements

Discount lift tickets are in and for sale - ski a day at the resorts and benefit the Utah Avalanche Center. Tickets for Alta, Brighton, Deer Valley, Solitude, and Snowbasin, Snowbird, and Sundance are in and more tickets are expected shortly.

Snowbird Mtn Resort requests that skiers and boarders accessing their terrain from the White Pine ridge or before or after normal operations please abide by their private land policies or check in with the ski patrol. Thanks.

Weather and Snow

Under mostly cloudy skies, temps are in the upper teens and low 20s. Winds, while energetic from the south and southwest yesterday, have since dropped below 15mph. Riding conditions are best in the wind sheltered mid and upper elevation terrain.

Recent Avalanches

Only one reported avalanche in the backcountry yesterday and it's worth writing home about. A skier remotely triggered a 18" deep and 50' wide avalanche on a repeater slope from the avalanche cycle on Nov 23rd. It ran 350' vertical. Enough wind had apparently built enough of a load over the re-built structure to allow for collapse failure on this north facing slope at 9600' in upper Little Cottonwood Canyon. I suspect there may be other areas like this in the Wasatch.

To be sure, this is an outlier - and while some of us had been thinking about this potential for repeater avalanches - the author Nassim Taleb makes the case well that it's much easier to reverse-engineer the event and trick yourself into believing you saw it coming. I speak not for the person who triggered the slide - I speak for myself. It's why it's difficult to relax with such a rickety foundation of snow.

Ad
Avalanche Problem #1
Persistent Weak Layer
Type
Location
Likelihood
Size
Description

Warming and time should conspire to make these wind drifts less sensitive today; still it'll be key to assess each slope for trouble - test slopes, ski and slope cuts, previous tracks, (tests and obs) are all good indicators of conditions. Click on the 'i' next to the Wind Slab icon for more info and travel advice.

Avalanche Problem #2
New Snow
Type
Location
Likelihood
Size
Description

It's undeniable that with so many dry periods this winter, we have a few weak layers within the snowpack: the early season facets from the Nov 2 storm...the facets from mid-November...the facets formed during the dry spell after Thanksgiving. (See Greg Gagne's snow profile below). These weak layers may lay dormant until another rapid loading event (heavy snowfall and/or significant wind)...or they may eventually become inactive all together. At this point, I'm inclined to believe that most - but not all - of these are dormant. More problematic is the absolute spatial variability of these weaknesses across the landscape, which is typical for early and/or dry seasons.

Problem - likelihood is low for triggering, size is enough to bury you or rake you through the rocks. Uncertainty is high.

Solution - avoid the northwest to northeast facing terrain altogether or choose lower angle slopes; those with a higher level of risk might otherwise set themselves up for success by choosing forgiving terrain - terrain without traps below (trees, cliff bands, steep-walled gullies).

For more info and travel advice, click on the 'i' next to the Persistent Slab icon

Additional Information

A number of weak systems will move through over the next several days though it shouldn't amount to much. We'll have mostly cloudy to overcast skies, southwesterly winds blowing 10-15mph, and temps in the mid- 20s at 10,000', the mid-30s at 8000'. Longer range models have a ridge building off the west coast with a few storms sliding into Utah on Sunday into Monday. They'll likely be warm and windy but at least the models are arguing over whether there'll be any precip or not.

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, 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)

EMAIL ADVISORY If you would like to get the daily advisory by email you will need to subscribe here.​

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.

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 with more resorts to come soon. 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. You can see the uphill travel policy for each resort here. IMPORTANT: Before skinning or hiking 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.

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.