Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Thursday - March 10, 2016 - 7:14am
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MODERATE (level 2): Heightened wind slab and cornice fall conditions exist, and you could trigger avalanches today in drifted upper and mid-elevation terrain. Loose wet avalanches entraining significant piles of fresh snow will become likely on steep slopes at all elevations with solar and daytime warming later in the day. Evaluate the snow and terrain carefully, and avoid and stay out from under steep sunny slopes as temperatures heat up.




current conditions

The Tony Grove Snotel at 8400' reports 30 degrees this morning and 9 inches of new snow yesterday morning containing an inch of water. There's 76 inches of total snow containing 97% of average water for the date. It's 25 degrees at the 9700' CSI Logan Peak weather station with southwest winds currently averaging 23 mph. Yesterday's surprise powder stayed pretty good up high with cool temperatures and clouds, but solar heating certainly affected lower elevation slopes and the snow became moist and sticky pretty quickly in the afternoon.
recent activity
  • A party of riders triggered a fairly large loose wet avalanche in a steep north facing chute in the Tony Grove Area Sunday (3-6-2016). The avalanche flushed all the heavy new snow out of the upper part of the gully and gouged out old snow down to rocks lower down, leaving an impressive pile of debris in the apron.

  • Tuesday we noticed a fair amount of recent wet activity on north and northeast facing mid elevation slopes in the Wood Camp Area. These likely occurred over the weekend with record warm temperatures on Saturday and rain and wind on Sunday.

  • Yesterday, triggered shallow wind slabs and cornice falls were common in the backcountry and as mitigation done at Ogden and Wasatch ski areas. By 2:30 in the afternoon, I was easily able to trigger loose wet sluffs entraining a few inches of new snow in sunny terrain at lower elevations in the Bear River Range.

This natural avalanche from over the weekend in the Wood Camp Area looks to have been initiated by either a cornice fall or a shallow wind slab, but it involved wet snow in descent. (3-8-16)

***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

Heightened cornice fall and wind slab avalanche conditions exist today in drifted upper elevation terrain.

  • Beware large overhanging ridge-top cornices, which could break further back than you expect and might trigger avalanches on drifted slopes below. Natural cornice falls are possible in some areas, especially during the heat of the day.
  • You're likely to trigger shallow wind slab avalanches on drifted upper elevation slopes. Avoid recent drifts on the lee sides of ridges, cross-loaded along sub-ridges, and in and around terrain features like rock outcroppings, gullies, scoops, trees, and saddles. Cracking is a sign of potential instability, and I triggered numerous shooting cracks in the fresh snow in drifted terrain yesterday. The new snow was not bonding well to the old yesterday, but I expect this instability to gain strength fairly quickly.

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

Powerful March sun and rapid warming today will quickly warm the new snow in sunny terrain, and the fresh snow will become moist and sticky and prone to avalanching. Avalanches starting as small point releases will entrain all the fresh snow in descent and could become quite sizable on long slopes with a sustained pitch. Natural loose wet avalanches are possible (and perhaps likely) on sunny slopes at all elevations during the heat of the day, and wet avalanches may become possible on shady low and mid elevation slopes as air temperatures skyrocket in the mountains.

weather

A warm southwest flow is developing over the region today and will increase through tomorrow. A weak system will cross over the zone on Saturday. A series of storms will begin to impact the region on Sunday and continue well into next week. Expect partly sunny weather today with southwest winds averaging in the mid teens along the ridges and a high temperature at 9000' around 48 degrees! It'll be partly cloudy tonight with a low around 34 degrees and a bit stronger southwest winds. It'll be partly cloudy again tomorrow with south southwest winds averaging in the mid twenties and mountain temperatures pushing 50 degrees again.
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. 

We'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.