Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Friday - February 5, 2016 - 7:00am
bottom line

MODERATE (level 2): Heightened avalanche conditions exist in the backcountry. Evaluate the snow and terrain carefully and make conservative decisions. Wind slab avalanches are likely in drifted upper elevation terrain where the danger is higher (level 3), and you could still trigger dangerous deep slab avalanches on some slopes steeper than about 30 degrees in isolated areas where a harder slab layer is overloading weak sugary or faceted snow near the ground.




current conditions

There's 8 inches of light new powder from the last 24 hous, and the temperature is 12 degrees this morning at the 8400' Tony Grove Snotel. There's 82 inches of total snow, containing 108% of average water content for the date. The 9700' CSI Logan Peak weather station reports 10 degrees and steady 10 to 15 mph wind from the northwest.
recent activity

A solo backcountry skier was tragically killed by an avalanche near Park City on Sunday and his body recovered Tuesday. Here is our Accident Report.

A Forest Service Utah Avalanche Center backcountry avalanche forecaster was caught, carried, partially buried and injured in a nasty deep slab avalanche in the Skyline Zone on Wednesday(2-3-16.) Accident Report

A FS Utah Avalanche Center avalanche forecaster was luckily only injured in this nasty deep slab avalanche in the Skyline backcountry Wednesday, 2-3-16.

  • We noticed a fresh deep slab avalanche on Monday in the Oscar Mayer slide path in Logan Dry Canyon. A local observer skied the line on Sunday afternoon before the east winds picked up Sunday night, and the sizable avalanche must have occurred overnight or early in the morning of February 1. Report is HERE
  • Looks like a fairly widespread natural avalanche cycle last weekend during the storm, with natural avalanches visible in the generally east facing avalanche paths in the Wood Camp Area and in the Wellsville Range.
  • A hiker on snow-shoes triggered and may have been caught in a loose avalanche at the mouth of Logan Dry Canyon Saturday. And, it looks like a pedestrian sledder might have taken a similar ride in loose snow over the weekend at the very bottom of Green Canyon.

    A video posted on Facebook from a large sled triggered avalanche (1-19-16) in Christmas Tree Bowl is .....HERE

***To view our updated list of backcountry observations and avalanche activity from around Utah, go to our observations page

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

Moderate but sustained northwest wind overnight drifted yesterday's light snow in exposed terrain, and you are likely to trigger fresh wind slab avalanches on steep drifted slopes in deposition zones at upper elevations.

  • Avoid fresh and forming drifts near ridge tops and in and around terrain features like gullies, sub-ridges, scoops, and rock outcroppings.
  • I expect these wind slabs will be relatively small and generally manageable. But, be aware of trees or other terrain traps on steep slopes below you.
  • Older stiff wind slabs failing on preexisting weak surface snow are also possible in some areas today. Hard wind slabs have the nasty tendency to sometimes allow you to get out on them before releasing.
  • The weight of a smaller wind slab avalanche overrunning a slope with poor snow structure could cause a step-down and a deeper much more dangerous avalanche.
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

A lingering possibility of triggering a dangerous deep slab avalanche exists in outlying terrain and on isolated slopes with shallow snow cover. The slopes we are concerned with have poor snow structure. Weak sugary or faceted snow near the ground overloaded by a slab layer of harder snow creates a potentially unstable situation. Beware areas that avalanched earlier in the winter, since weak snow remained in the bed surfaces and the areas remained shallow. Weak snow structure exists mainly in areas where the total snow is 3' deep or less. Avalanches are most likely in shallow rocky upper elevation terrain, but the shallow snow is still also weak in many areas at lower and mid elevations. I'm finding propagation in most of my snowpit tests in shallower snow this week, with failures common in loose sugary faceted snow in the basal layers.

***Pay close attention to signs of unstable snow like recent avalanches, whumpfing, and shooting cracks, and be willing to reevaluate your plans. In these conditions you could trigger avalanches remotely, from a distance or worse, from below!
weather

The final system in the recent stream of storms is heading off to the east this morning and a strong high pressure system will build over the area. High pressure will become quite strong over the entire region this weekend and through early next week. It'll be mostly cloudy today with isolated snow showers possible, moderate northwest wind, and a high temperature at 8500' around 21 degrees. The sun may pop out occasionally. It'll be mostly cloudy tonight, and warmer tomorrow, with a high temperature around 27 degrees.

general announcements

Please submit snow and avalanche observations from your ventures in the backcountry HERE. You can call us at 801-524-5304 or email HERE, or include #utavy in your Instagram or Tweet us @UAClogan. To report avalanche activity in the Logan Area or to contact the local avalanche forecaster call me, Toby, at 435-757-7578. 

I'll update this advisory throughout the season on Monday, Wednesday, Friday, and Saturday mornings by about 7:30

This advisory is produced by the U.S.D.A. Forest Service, which is solely responsible for its content. It describes only general avalanche conditions and local variations always exist.