Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Sunday - December 27, 2015 - 7:26am
bottom line

CONSIDERABLE (level 3): Dangerous avalanche conditions still exist in the backcountry, especially in drifted terrain at upper and mid elevations. Large and destructive triggered avalanches are possible in some areas. You might trigger avalanches remotely, from a distance or possibly from below. Careful snowpack evaluation, cautious routefinding and conservative decision-making will be essential in the backcountry this weekend.




special avalanche bulletin

THIS SPECIAL AVALANCHE ADVISORY IS FOR THE MOUNTAINS OF NORTHERN UTAH, TO INCLUDE SOUTHEAST IDAHO, THE BEAR RIVER RANGE, THE  WASATCH RANGE, AND THE WESTERN UINTAS.

HEAVY SNOW AND STRONG WINDS HAVE LED TO DANGEROUS AVALANCHE CONDITIONS WITH MANY AVALANCHES BREAKING TO THE GROUND.

AVOID BEING ON OR BENEATH STEEP TERRAIN AS THESE AVALANCHES MAY BE TRIGGERED FROM BELOW.

THIS ADVISORY DOES NOT INCLUDE SKI AREAS OR HIGHWAYS WHERE AVALANCHE CONTROL IS NORMALLY DONE. FOR MORE INFORMATION VISIT WWW.UTAHAVALANCHECENTER.ORG OR CALL 1-888-999-4019.

current conditions

You'll be able to find nice deep powder riding conditions in the backcountry this weekend, and if you stick to lower angled, lower elevation, and sheltered terrain you'll be able to have fun and be safe. Heavy snowfall and sustained winds overloaded a widespread weak preexisting base, creating dangerous avalanche conditions in many areas. History tells us we're set up for avalanche accidents on a sunny weekend day after a major storm and natural avalanche cycle as the snow only gradually becomes more stable. On days like these people are likely to be lured by the powder sirens into steep drifted terrain. Resist the urge this weekend, and stick to slopes less than 30 degrees, play in the deep powder meadows well out from under the steeper hills, or explore those secret lower elevation powder stashes.

You'll be able to find great powder riding conditions in the backcountry this weekend. If you stick to lower angled terrain and stay off and out from under steep slopes, you'll be able to have fun in the deep powder and stay safe. (12-24-15)


After a very productive pre-Christmas storm, the Tony Grove Snotel at 8400' reports a gain of 5.3" of water and a few feet of snow since last weekend. The station is showing significant settlement of the fresh powder despite cold temperatures. It's 15 degrees this morning and there's 58 inches of total snow, containing 106% of average water content for the date. It's 11 degrees at the 9700' CSI Logan Peak weather station, which is showing light east winds this morning.


recent activity


Evidence of natural activity from the prolonged pre-Christmas storm is visible from Cache Valley, and looks to have been fairly widespread across the zone... Looks like a number of good sized avalanches occurred early in the storm, Monday Night or Tuesday and also several more recent. Of greater concern are the many suspect steep slopes and avalanche paths in the area that do not show any signs of recent natural activity. Many of these may sitting in a balanced state, just lying in wait for a person to trigger.

There was extensive natural avalanche activity in upper Providence Canyon, with large avalanches having occurred at different times during the pre-Christmas Storm. Most of the large paths in the area avalanched. Pictures above are of Three Terraces Bowl and the crown of a slide on the north side of Providence Peak. Both look to have gone big around Christmas Eve. I think the activity was natural, but being in such a popular riding area, some of the avalanches may have been remote triggered.(12-26-15)


  • Saturday (12-19-15): A very experienced local rider is lucky to be alive after triggering a good sized avalanche, being caught and carried through thick trees, and then being mostly buried and trapped in the debris. See Video Report

***To view our updated list of backcountry observations and avalanche activity from around Utah, go to our observations page


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

Widespread very weak snow is now overloaded by a few feet of heavier drifted snow and deceptive powder, and dangerous avalanche conditions probably still exist in some areas. Settlement and cold temperatures have helped to stabilize the snow, but dangerous deep slab avalanches remain possible today, especially in drifted terrain at upper and mid-elevations.


***You should give avalanche paths and slopes steeper than about 30 degrees more time to strengthen after the huge load they received earlier on the week It'll be wise to continue to avoid drifted slopes steeper than about 30 degrees, but if you venture into the backcountry, pay close attention to signs of unstable snow like recent avalanches, whumpfing, and shooting cracks, and be willing to reevaluate your plans. In these conditions you could trigger avalanches remotely, from a distance or worse, from below!

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 smaller wind slab avalanche overrunning a slope below could trigger a larger and more destructive avalanche involving old weak snow.

weather

High pressure conditions will develop today, with 8500' high temperatures around 20 degrees and light and variable winds. A series of weak troughs will cross over the zone Monday through Wednesday, and high pressure conditions will redevelop later in the week and for New Years Day.

general announcements

Please submit snow and avalanche observations from your ventures in the backcountry HERE. You can call us at 801-524-5304 or email HERE, or include #utavy in your Instagram or Tweet us @UAClogan. To report avalanche activity in the Logan Area or to contact the local avalanche forecaster call me, Toby, at 435-757-7578. 

I'll update this advisory throughout the season on Monday, Wednesday, Friday, and Saturday mornings by about 7:30

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.