Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Friday - January 20, 2017 - 7:03am
bottom line

The overall avalanche danger is LOW and the snow is stable on most slopes. However, pockets with heightened danger exist in upper elevation terrain, and triggered wind slab avalanches and cornice-falls are possible. Use normal caution and evaluate the snow and terrain carefully, especially at upper elevations. Avoid steep drifted slopes.




special announcement

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current conditions

The Tony Grove Snotel at 8400' reports 21 F and 2 inches of light snow in the last 24 hrs. There is 88 inches of total snow containing 156% of average SWE (Snow Water Equivalent). It's 14 F at the CSI Logan Peak weather station at 9700', with a 3 mph southwest wind. South winds calmed yesterday around midday and remained light overnight. We found nice loud powder riding yesterday on re-crystallized surface snow and surface hoar, with a variable sun-crust on slopes facing even a little southward. As we had hoped, wind, sun, and warmth destroyed the well developed surface hoar on many slopes before it could be buried and preserved. Unfortunately, this is not true in some areas, where yesterday's light snow gently capped the delicate weak surface snow, and we'll have to suspect and check for the existence of ​this buried persistent weak layer in the future.


Surface hoar is widespread in the Logan Zone and it's now buried and preserved by a couple inches of light snow on some slopes.
recent activity

No new avalanches have been reported since last week's widespread, natural avalanche cycle.

Large, natural avalanches from last week in the Wellsville Range above Mendon.
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

South winds yesterday morning created pockets with heightened danger of wind slab avalanches in exposed upper elevation terrain.

  • Drifts likely formed on weak surface snow consisting of surface hoar and/or small-grained sugary faceted snow, and fresh wind slabs could still be sensitive to triggering.
  • Wind slabs made up of stiffer drifted snow are often 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.
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

Deep slab avalanches, failing on buried weak layers, are unlikely but possible.

  • Large, natural avalanches stepping into old snow were common during last week's storm at all elevations.
  • Weak layers of faceted snow exist above and below rain-crusts at mid and lower elevations.
  • The snow is weakest in rocky terrain where it's thin or shallow, and we've found some areas still plagued by depth hoar near the ground.
  • These types of avalanches are low probability - high consequence, meaning you're unlikely to trigger one, but if you get caught, you could get killed or seriously injured.
weather

The active weather pattern will continue across the region, with a series of weather systems crossing the area through the first half of next week. It'll be mostly cloudy today with a high temperature at 8500' of 27 F, 5 to 8 mph south-southwest winds, and a 40% chance of a half inch of snow. Snow is likely tonight with increasing south winds, a low temperature of 19 F, and 1 to 3 inches of snow. Snow will continue tomorrow with moderate southwest winds, high temperature of 27 F, and 1 to 3 inches of snow. A stronger wave of Pacific storminess will bring more snow Sunday night and Monday, with breezy conditions and 7 to 15 inches of snow possible.
general announcements

Any time 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

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.