Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Tuesday - March 29, 2016 - 7:44am
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CONSIDERABLE (level 3): Dangerous avalanche conditions probably already exist on some upper elevation slopes, and continued snowfall and winds today will cause the danger to rise and become more widespread. Human triggered storm snow and wind slab avalanches are likely and natural avalanches are possible, most likely during periods with particularly heavy snowfall. Evaluate the snow and terrain carefully, especially at upper elevations on slopes with significant fresh accumulations and avoid steep drifted slopes.




current conditions

The Tony Grove Snotel at 8400' reports 30 degrees and a storm total so far of 11 inches of new snow with 1" of water in the past 36 hours. There's 98 inches of total snow containing 106% of average water for the date. I'm reading 22 degrees at the 9700' CSI Logan Peak weather station, with south-southwest winds currently averaging 15 mph. Sustained east winds averaging 20+mph and gusting into the forties overnight easily found fresh snow to drift and likely created wind slabs in rather unexpected places. You'll find good powder conditions today, but dangerous wind slab avalanche conditions probably already exist in some areas and continued snowfall and wind today could cause the danger to become more widespread.

This morning's 4km water vapor image, showing the current storm and moisture rotating over the Logan Zone from the east and north.

recent activity
  • No avalanches were reported locally from over the weekend.
  • A natural wind slab avalanche under the cliffs of Boiler Buttress in Steam Mill Canyon was triggered by overrunning snow from a wet sluff from the cliffs above midday Wednesday. (3-23-16) .........Report and Photos

​***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

Expect heightened storm snow avalanche issues as more snow accumulates in the mountains today. Soft slab avalanches may fail on the old snow surface or on a density change or weak layer within the new snow. Loose sluffs are likely in steep terrain and natural activity involving the new snow will be most likely during periods of particularly heavy snowfall.

Loose wet avalanches involving the fresh snow will be likely when the fresh snow is initially warmed, especially if the sun pops out unexpectedly...
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

Dangerous avalanche conditions probably already exist in some upper elevation areas, and wind slabs will continue to develop today as new snow piles up and is drifted into upper elevation deposition zones. Human triggered wind slabs are likely and naturals possible today in some drifted upper elevation terrain. Somewhat unusual east winds, (from the opposite direction of local prevailing winds,) overnight probably created drifts in unexpected places.

  • Watch for and avoid drifted snow 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 in the snow surface is a sign of potential wind slab instability.
  • Beware large overhanging ridge-top cornices, which could break further back than you expect and might trigger avalanches on drifted slopes below.

Cracking like this is a red flag indicating potential soft slab instability. (3-23-16)
weather

THE COLD UPPER LEVEL LOW PRESSURE SYSTEM ALONG THE UTAH AND NEVADA WILL DRIFT SLOWLY SOUTH THROUGH EARLY WEDNESDAY. THIS LOW PRESSURE WILL WEAKEN ON WEDNESDAY...AND WILL BE REPLACED BY HIGH PRESSURE ALOFT FOR THE UPCOMING WEEKEND.

Weather Forecast: Tony Grove Lake (41.897,-111.6535), Elevation: 8800'
Today: Snow. High near 28. East southeast wind 5 to 14 mph becoming southwest in the afternoon. Chance of precipitation is 100%. Total daytime snow accumulation of 3 to 7 inches possible.
Tonight: Snow. Low around 21. Light and variable wind becoming east 9 to 14 mph in the evening. Chance of precipitation is 80%. New snow accumulation of 3 to 5 inches possible.
Wednesday: Snow, mainly before noon. High near 30. East wind 6 to 9 mph becoming north northwest in the afternoon. Chance of precipitation is 80%. New snow accumulation of around an inch possible.

general announcements

The National Avalanche Center recently completed an animated tutorial on the North American Avalanche Danger Scale.  HERE

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.