Avalanche Advisory
Advisory: Provo Area Mountains Issued by Evelyn Lees for Saturday - December 21, 2013 - 7:07am
bottom line

There is a HIGH avalanche danger on upper elevation, northwest through north through easterly facing slopes. Dangerous, deadly avalanche conditions exist - large slides 200-300 feet wide and 2 to 4 feet deep can be triggered, breaking near the ground. CONSIDERABLE danger exists on other steep mid and upper elevation slopes on the north ½ of the compass. Slides can be triggered from a distance and from below.

GO TO: Recreate on lower angle slopes, less steep than about 35 degrees, in wind sheltered terrain, avoiding travel below steeper slopes. Backcountry travelers need excellent route finding and decision making skills. OR head to one of the resorts or groomed cross country ski tracks.




special avalanche bulletin

A SPECIAL AVALANCHE ADVISORY HAS BEEN ISSUED FOR THE MOUNTAINS OF NORTHERN UTAH TO INCLUDE THE WESTERN UINTAS. DANGEROUS HUMAN TRIGGERED AVALANCHES MAY BE TRIGGERED IN STEEP WEST TO NORTH TO EAST FACING TERRAIN ABOVE 8000` IN ELEVATION. EXPERT ROUTE-FINDING IS REQUIRED FOR SAFE TRAVEL IN THE MOUNTAINS.  THIS ADVISORY DOES NOT INCLUDE SKI AREAS OR HIGHWAYS WHERE AVALANCHE CONTROL IS NORMALLY DONE.

special announcement

The Utah Avalanche Center wishes you a safe and powder-filled holiday season. Please consider the UAC in your holiday giving plans - your donations pay for these advisories and we can't do this without your help. What is it worth to you every day to get an avalanche and mountain weather advisory? The cost of a beverage or the gas it takes to get up the canyon? You can donate here.

current conditions

Light snow is just starting to fall in the Provo mountains, with 1 inch so far. Temperatures are in the teens, and the westerly winds have kicked up in the last few hours – 15 to 20 mph averages, with gusts in the 30s. Across the highest ridge lines, wind speeds are exponentially stronger – 30 to 40 mph averages, with gusts close to 50 at times. Combined with Thursday’s storm, today’s snow is doing a great job freshening up the old snow surface with soft powder.

recent activity

No new reports from the Provo area mountains, but the Salt Lake and Park City mountains make up for it. There were at least 7 human triggered slides yesterday – 3 along the Park City ridgeline, including 2 snowmobile triggered slides in White Pine, 3 out-of-bounds around the Brighton perimeter, with the largest, in Hidden Canyon, about 200’ wide, resulting in a long ride and almost full burial, but thankfully no injuries, and a smaller slide in Grizzly Gulch. All these slides were above 9,000', on northwest through north through easterly facing slopes, and most are breaking near the ground. Mark White photo below of a sledder triggered White Pine slide.

Avalanche control work with artillery and explosives produced significantly larger slides in the Salt Lake and Park City mountains on similar slopes, up to 800’ wide, again breaking near the ground. Ski cuts for control work were also producing slides 60-80’ wide failing near the ground.

Avalanche Problem 1
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 12 hours
description

The snowpack is unstable – on many slopes all it is going to take is a trigger – which is YOU or you and your sled. Almost every slide the past 2 days is eventually breaking deep, near the ground, on one of several weak layers of facets. Avoid travel on all steep slopes facing northwest through north through east.

These slides are not “manageable”, and on-slope forecasting doesn’t work for this weak layer – small slides can step down, slides can be triggered from a distance, from below, could break out above you, or on the second or third person.

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

The westerly winds are blowing and transporting snow – any fresh drifts will be sensitive and easy to trigger. While drifts will be most wide spread on easterly facing slopes, avoid all new drifts on any steep slope. This danger increases dramatically with elevation, because the winds are much stronger along the high ridgelines. Any triggered wind slab could step down and trigger a much larger slide.

weather

Light snowfall today will bring an additional 4 to 8 inches of cold, dry powder. Unfortunately, the elevated wind speeds will continue throughout the day – averaging 10 to 20 mph from the northwest, gusting in the 30s. And along the high ridges, speeds are verging on out of control, with averages to 40, gusts in the 60s. Temperatures will remain in the teens at 10,000’ and warm into the mid-20s at 8,000’. Snow will taper off tonight and skies partially clear. Additional light snow is possible Monday night into Tuesday.

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.