Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Saturday - February 18, 2017 - 6:59am
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The danger is MODERATE and heightened avalanche conditions exist in the backcountry. Triggered wind slab avalanches are possible on drifted upper elevation slopes. Snow is stable in most other terrain, but shallow wet avalanches entraining saturated surface snow are possible on shady slopes in the heat of midday. Use normal caution, avoid drifted slopes at upper elevations and steep slopes with saturated surface snow above trees, cliffs, or other terrain traps.
special announcement

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.

current conditions

The 8400' Tony Grove Snotel reports 32 F, 3" of new snow, and a bit of rain overnight. There's 100" of total snow containing 160% of average SWE (Snow Water Equivalent) . It's 25 F at the CSI Logan Peak weather station at 9700', and the wind is from the south at 31 mph, gusting to 56 mph early this morning. The fresh snow will help freshen-up and smooth-in variable and crusty backcountry snow conditions. Soft, shallow, re-crystallized snow exists on shady upper elevation slopes, with melt-freeze crusts or slushy surface snow elsewhere. Not far under the snow surface at all elevations is a thick and hard crust formed by warmth and copious rain last week. Wind slab and loose avalanches involving the surface snow are possible, but the thick and bomber crust is holding the deeper snowpack together.

recent activity
  • Numerous shallow sled and board triggered wind slabs were reported from drifted upper elevation terrain in the Bear River Range last weekend and early this week. The expected and easily triggered shallow soft slab avalanches occurred on very steep slopes, and were about 8" deep. Several triggered wet and dry sluffs were also reported.
  • Warmth trapped by thin clouds affected the snow on north facing mid-elevation slopes, and my party triggered a few small wet sluffs in south Wood Camp Thursday afternoon.
  • Thursday, a party observed a huge cornice that had recently cracked deeply and collapsed on the ridge above DB Bowl in Logan Dry Canyon. There were sled tracks in the area of the fracture, but it's unknown if the collapse was triggered or if it occurred after the fact.

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
  • Triggered wind slab avalanches are possible at upper elevations. Strong south winds overnight drifted fresh snow into terrain features and lee slope starting zones, creating shallow wind slabs. Drifts at upper elevations formed on weak faceted snow above last week's thick crust and could be pretty sensitive today. Wind slab avalanches could run fast and far on last week's rain-crust.
  • Avoid drifted snow on the lee side of ridges and in and around terrain features like gullies, scoops, sub-ridges, and cliff-bands.
  • Wind slabs made up of stiffer drifted snow often look rounded and chalky and may produce hollow, drum-like sounds.
  • Cornices are suspect due to the recent warmth and wind. Avoid travel on or below large overhanging cornices, especially in the midday heat. Cornices can break further back than expected and might 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

As the shallow soft snow at mid-elevations is warmed by daytime heating, it'll be prone to sluffing. Warm temperatures again today will cause an increasing danger of shallow loose wet avalanches on steep slopes. Triggered wet sluffs will entrain a few inches of sloppy, saturated snow and run on last week's thick crust.

Triggered wet sluffs above Tony Grove Lake (Flygare 2-13-17)
weather

The upper level trough along the California coast will work slowly east across the desert southwest and Great Basin through the weekend. High pressure aloft will return early next week, followed by a new and rather cold storm system arriving midweek. It'll be cloudy today in the mountains, with a chance of snow, 8500' high temperature of 38 F, and 15 to 20 mph south wind. 1 to 2 inches of new snow is likely tonight, with a low temperature of 29 F, and 11 to 13 mph south wind. It will snow tomorrow, with 3 to 7 inches possible, a high temperature of 35 F, and 10 to 15 mph west wind.
general announcements

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

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.

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.