Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Sunday - February 5, 2017 - 7:12am
bottom line

Warm temperatures and saturated snow are causing dangerous wet avalanche conditions on steep low elevation slopes. Drifting from sustained southwest wind created heightened wind slab avalanche conditions in exposed upper elevation terrain. Evaluate snow and terrain carefully, avoid and stay out from under steep slopes with saturated snow and those with drifted snow.




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current conditions

The 8400' Tony Grove Snotel reports 2 inches of new snow with .3" SWE ‚Äč(Snow Water Equivalent) in the last 24 hrs. It's 30 F and there is 96" of total snow containing 152% of average SWE. It's 24 F at the CSI Logan Peak weather station at 9700', and the wind is from the southwest at 19 mph, gusting to 40 mph. Triggered wind slab avalanches are possible in drifted terrain. Yesterday the snow on low elevation slopes was soggy from warmth, and there were many natural avalanches at lower elevations.

recent activity

Several sizable natural loose wet avalanches hit the Logan River, and one crossed Hwy 89 in the Dugway section of Logan Canyon. Large natural wet avalanches occurred overnight and during the day Saturday at low elevations in various canyons across the Logan Zone.

Natural loose wet avalanches in the Logan River and Cowley Canyon

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

Dangerous wet avalanche conditions exist on slopes with saturated snow. Natural sluffs entraining loose wet snow are likely at lower elevations, and triggered wet slab avalanches are possible on slopes with buried persistent weak layers. Avoid and stay out from under steep slopes with wet snow.

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 from southwest winds created fresh wind slabs and built cornices in exposed terrain.
  • Wind slabs made up of stiffer drifted snow often look rounded and chalky and may produce hollow, drum-like sounds.
  • Avoid drifted snow on the lee side of ridges and in and around terrain features like gullies, scoops, sub-ridges, and cliff-bands.
  • Cornices could break further back than expected and may trigger avalanches on drifted slopes below.
Avalanche Problem 3
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 24 hours
description

Triggered persistent slab avalanches around 2 feet deep are possible in isolated mid-elevation terrain.

  • Buried surface hoar exists mainly in sheltered mid and lower elevation terrain, but is found on east, north, and west facing slopes.
  • A weak layer of small facets on top of a sun-crust still plagues some sunny mid elevation slopes.
  • You will have to dig down into the snow a couple feet to find the buried persistent weak layers.



    I found saturated surface snow on all aspects and buried surface hoar about 1' deep in Tab Hollow yesterday (2-3-17).

weather

Weak high pressure aloft across the region today will give way to an active and wet weather pattern Monday through much of the week.

Weather Forecast: Tony Grove Lake (41.897,-111.6535), Elevation: 8800'
Today: A 50 percent chance of snow. Cloudy, with a high near 31. West southwest wind 14 to 16 mph. Total daytime snow accumulation of 1 to 2 inches possible.
Tonight: Snow likely, mainly after 11pm. Cloudy, with a low around 28. Southwest wind 15 to 18 mph. Chance of precipitation is 70%. New snow accumulation of 1 to 3 inches possible.
Monday: Snow. High near 32. Windy, with a west southwest wind 25 to 31 mph, with gusts as high as 45 mph. Chance of precipitation is 90%. New snow accumulation of 2 to 4 inches possible.
Monday Night: Snow. Low around 24. Windy, with a west wind 31 to 38 mph, with gusts as high as 55 mph. Chance of precipitation is 90%. New snow accumulation of 3 to 5 inches possible.

general announcements

Any time is a great time to practice companion rescue techniques with your partners. Companion Rescue Practice Video

If you sign up for AmazonSmile and designate the Utah Avalanche Center as your favorite charity, they will donate a portion of everything you spend to the UAC. It doesn't cost you a penny and we'd really appreciate the help.

Discount lift tickets for Beaver Mountain, Snowbasin, Powder Mountain, and the Central Wasatch resorts are donated by the resorts to benefit the Utah Avalanche Center. Details and order information here.

Your information can save lives. If you see anything we should know please help us out by submitting snow and avalanche observations. You can call us at 801-524-5304, email by clicking HERE, or include @utavy in your Instagram. In the Logan Area you can reach me at 435-757-7578

We will update this advisory regularly on Monday, Wednesday, Friday, and Saturday mornings by about 7:30.

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 exist.