Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Monday - December 30, 2013 - 6:47am
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Dangerous avalanche conditions still exist in the Logan Area backcountry, and there is a Level 3 or CONSIDERABLE danger on drifted upper elevation slopes. Triggered persistent slab avalanches remain probable on some slopes at upper elevations due to recent slab development and very weak preexisting faceted snow. Wind slab avalanches are possible in drifted upper and mid-elevation terrain. You might trigger avalanches remotely, from a distance or below. Careful snowpack evaluation, cautious route-finding, and conservative decision making continue to be essential for safe travel at upper elevations in the backcountry. You'll find more stable and safer conditions in sheltered mid-elevation terrain and at lower elevations though the snowpack is still quite shallow, and the danger of hitting rocks and down trees is significant.




special announcement

-Sign up now for our Avalanche 101 course to be held in Logan on January 9 and 11................. Information and registration

-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

current conditions

The Tony Grove Snotel at 8400' reports 22 degrees this morning, and there is 33 inches of total snow containing 69% of average water content for the date. The 9700' Logan Peak weather station reports 14 degrees and west northwest wind, currently averaging in the mid-twenties. You can find pretty nice re-crystallized powder conditions in sheltered shady terrain, but you tend to break through a widespread brittle rime-crust on the surface or buried under a few inches of fresher snow from early Christmas Eve. Westerly winds scoured the fresh snow and the translucent crust is now on the surface on the ridges and exposed south and west facing slopes, making for tricky traveling in places. You'll still find pockets of dangerous avalanche conditions at upper elevations in the Logan Area backcountry.

Looking west into the Mount Naomi Wilderness from the Cornice Ridge Area on 12-26-2013.

recent activity

A fairly widespread natural avalanche cycle occurred in the Central Bear River Range as an energetic cold front passed through the region early Christmas Eve. The hard and soft slab avalanches occurred on northwest, north, northeast, east, and southeast facing slopes above around 8200' in elevation. They ranged from fairly small (around a foot deep and 30' wide) to pretty big, like the ones on Cornice Ridge and in the Mount Naomi Wilderness that were both around a meter deep and a 1/4 to 1/2 mile wide... A more recent natural slab release was also observed north of Mount Elmer during the recent warm and sunny spell on 12-27-2013.

Here's a look at a the broad crown of a natural avalanche in the Mount Naomi Wilderness that occurred early Christmas Eve.

A video look at the Cornice Ridge Avalanche from 12-26-2013 observation......... HERE

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

The new snow from just before Christmas piled up and was drifted onto preexisting very weak sugary or faceted snow, which is widespread in the region, creating a slab layer on many slopes. Dangerous human triggered avalanches failing in old weak faceted snow or in the basal layers of the existing snow pack remain likely in some areas facing northwest through east, especially in drifted upper elevation terrain. You could trigger persistent slab avalanches remotely or from a distance, or worse, from below. Collapsing and/or shooting cracks are obvious red flags requiring you to reevaluate your route.

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

Drifting of last weekend's snow caused the development of wind slabs, in many cases on top of very week preexisting snow. Heightened wind slab avalanche conditions remain in exposed upper and mid-elevation terrain. Triggered wind slab avalanches are possible on steep slopes with recent and older deposits of drifted snow. You'll find wind slabs composed of stiffer snow in exposed lee slope terrain, especially in and around terrain features like gullies, scoops, sub-ridges, rock outcroppings, and cliff bands. We recommend that you continue to avoid travel in steep drifted terrain.

weather

It'll be mostly cloudy today in the mountains, with 8500' high temperatures around 29 degrees and west winds in the 13 to 17 mph range. There is a chance for a little snowfall before the New Year (Tuesday and Tuesday night) and there's some hope that the inversions will weaken, but we don't expect much in the way of accumulation in the mountains. We'll likely see a bit of sun and partly cloudy conditions in the mountains the first couple days of the New Year. Looking towards the end of the week for a possible change in the stagnate weather pattern, but the models are still in disagreement, so lets not get our hopes up yet.

Check out our one stop weather page........HERE

general announcements

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.

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

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

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.

Sign up early for one of our life-saving avalanche classes.......HERE           And refresh your avalanche knowledge, check out some of our tutorials........HERE

Follow us at UAClogan on Twitter 

I'll issue these advisories on Monday, Wednesday, Friday, and Saturday mornings. 

This advisory is produced by the U.S.D.A. Forest Service, which is solely responsible for its content. It describes only general avalanche conditions and local variations always exist.