Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Monday - March 6, 2017 - 7:08am
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There's a CONSIDERABLE danger on drifted upper and mid-elevation slopes. Dangerous conditions exist, triggered wind slab and cornice fall avalanches are likely and naturals possible. Continuing drifting from strong west-southwest winds today and tonight will cause the danger to increase and become more widespread. Triggered soft slab and loose avalanches involving new snow are possible, even in sheltered terrain. Carefully evaluate snow and terrain, make conservative choices, and stay off and out from under drifted slopes and large cornices.




current conditions

The Tony Grove Snotel ​at 8400' reports 10 F and 13" of new snow and 1.2" SWE (Snow Water Equivalent.)​ There's 126" of total snow with 169% of average SWE. It's 2 F at the 9700' CSI Logan Peak weather station, and west wind is blowing 11 mph, gusting to 42 mph. The UDOT Hwy 89 Logan Summit reports 25 mph west-northwest winds overnight, with 40 mph gusts. Dangerous avalanche conditions exist on drifted upper and mid elevation slopes, and continuing strong west-southwest wind today will create larger and harder drifts and cause the danger of wind slab and cornice fall avalanches to increase and become more widespread.

The underlying snowpack is deep and generally stable, so avalanche activity will be confined to upper layers and the new snow. Mark Staples and I looked at snow in Franklin Basin on Saturday, and this is what we found:

recent activity
  • A rider triggered a good sized wind slab avalanche while side-hilling Friday afternoon just north of the ID/UT state line near Gibson Basin.
  • A large cornice fall avalanche occurred in upper Providence Canyon over the weekend. Here's a Facebook video showing the aftermath.... HERE

Rider triggered avalanche near Hidden Lake, Gibson Basin, ID (3/3/17)
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

Strong westerly winds overnight formed fresh wind slabs and enlarged already huge ridge-top cornices.

  • Avoid wind slabs on the lee side of ridges and in and around terrain features like gullies, scoops, sub-ridges, and cliff-bands.
  • Huge, overhanging cornices can break further back than expected and trigger avalanches on slopes 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

Triggered soft slab and loose avalanches involving the fresh snow are possible on slopes steeper than about 30 degrees, even in sheltered terrain.
weather

A cold Pacific trough will continue to cross the region today. A mild westerly flow aloft will follow for the middle and latter portions of the week. Snow showers will continue today, 3 to 5 inches of snow is possible, high temperature at 8500' of 16, and 22 to 30 mph west-southwest wind, gusting to 44 mph. 4 to 8 inches of snow is possible tonight, low temperature of 16 F, and 35 to 40 mph west-southwest wind, gusting to 60 mph. Snow is likely tomorrow, with 2 to 4 inches possible, high temperature of 26 F, and gradually decreasing west-southwest winds 35 mph in the morning and 25 mph by afternoon.
general announcements

Do you buy groceries at Smiths? When you register your Smith’s rewards card with their Community Rewards program, they will donate to the Utah Avalanche Center whenever you make a purchase. It's easy, only takes a minute, and doesn't cost you anything. Details here.

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.

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.

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.