Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Saturday - January 7, 2017 - 7:00am
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Heightened conditions exist and triggered avalanches are possible on steep slopes at all elevations. South winds increased overnight and wind slab avalanches are most likely in upper elevation terrain exposed to recent drifting. Persistent slab avalanches, including old snow and failing on buried weak layers, are possible on many slopes. Warmth and potential rain this weekend will create a significant danger of loose wet avalanches at lower elevations and of snow and ice falling off roofs in Cache Valley.




current conditions

The Tony Grove Snotel at 8400' reports 10 degrees F with 66" of total snow containing 128% of average SWE (Snow Water Equivalent). It's 12 degrees F at the CSI Logan Peak weather station at 9700', south winds increased overnight and are currently 25 mph, with gusts to 35 mph. Very cold temperatures for the past couple days kept the powder riding nice, even on south facing and low elevation slopes. Natural avalanches occurred during the storm across the zone including at low elevations in the foothills and farm fields, and lingering instability could affect people who usually don't need to worry about avalanches.

Climbing temperatures and rain at lower elevations will create serious problems this weekend. The Cache County Sheriff is warning of significant potential for flooding, and avalanches may become likely in unexpected low elevation terrain. Wet avalanches at lower elevations can threaten runners, dog walkers, fishermen, and children innocently playing in the snow. One of our biggest concerns with the warmth and possible rain is potential for roof avalanches down in the valley. Watch out for snow and ice falling off buildings and don't let the kids play where snow from the roof could slide down on top of them.

recent activity

Natural activity was widespread across the Logan Zone during Wednesday's storm, with avalanches at all elevations and on most slope aspects. The activity included widespread natural avalanches at low elevation, some down in Cache Valley.


These low elevation avalanches near Mendon occurred Wednesday night during the intense storm.

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

Drifting snow created heightened wind slab avalanche conditions in exposed terrain. Triggered wind slab avalanches are possible on drifted slopes steeper than 30 degrees at all elevations.

  • Today's stiff wind slabs will likely be stubborn and may allow you to get out on them before releasing.
  • Wind slabs are 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 wind slab avalanches on drifted slopes below.

Ongoing wind drifting and natural avalanche activity on Providence Peak Thursday, 1/5/2017 (Cory Lundahl)
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
  • Recent storms buried weak surface snow made up of surface hoar and/or near surface facets. On slopes where this weak snow was preserved by the light snow and not destroyed by warmth or wind, triggered avalanches are possible. Avalanches failing on surface hoar can occur on surprisingly low angled slopes, and many experienced people have been fooled by this tendency.
  • Weak layers of small-grained near surface facets exist above and below rain-crusts at mid and lower elevations, and avalanches stepping into old snow are possible at all elevations.
  • Dangerous deep slab avalanches, failing on depth hoar near the ground are unlikely but still possible, especially on rocky upper elevation north facing slopes with shallow snow cover.
  • Remotely triggered avalanches are possible.
weather

Expect mostly cloudy conditions in the mountains, with snow in the afternoon. High temperatures at 8500' will reach 23 degrees, with southwest winds 15 to 25 mph. An inch of snow may accumulate by evening. Snow is expected tonight, 4 to 8 inches possible, with west winds and temperatures rising to around 28 degrees. Temperatures will rise above freezing at 8500' on Sunday and rain is likely at low elevations. 8 to 14 inches of snow is possible Sunday and Sunday night, with increasing southwest wind and mild temperatures. Strong southwest winds and mild temperatures will continue through Monday, with 10 to 18 inches of additional snow possible by Tuesday morning.
general announcements

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

The National Avalanche Center just released their Avalanche Problems Explained video... Not all avalanches are made the same. As a result, travel and decisions in avalanche terrain are influenced by the kind of avalanche you expect to encounter. Watch HERE

Check out Avalanche Canada's "Rescue at Cherry Bowl" story 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.

Between now and Jan 15th: Donate to the Utah Avalanche Center by shopping at Whole Foods Market Utah! When you visit any Utah Whole Foods Market locations, bring your re-usable bags, Whole Foods will donate a dime per bag to the Utah Avalanche Center - if you say DONATE my bag credit.

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.