Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Saturday - February 6, 2016 - 6:54am
bottom line

MODERATE (level 2): Heightened avalanche conditions exist in the backcountry. Evaluate the snow and terrain carefully and make conservative decisions. Triggered wind slab avalanches are likely in drifted upper elevation terrain where there may be pockets of higher danger (level 3). Although gradually becoming less likely, you still might trigger dangerous deep slab avalanches on some isolated steep slopes where a harder slab is overlaying weak faceted snow near the ground. Direct solar warming, or greenhousing could create heightened loose wet avalanche conditions, and natural wet avalanches are possible in some areas.
current conditions

The temperature is 20 degrees this morning at the 8400' Tony Grove Snotel, and there's 78 inches of total snow, containing 107% of average water content for the date. The 9700' CSI Logan Peak weather station reports 15 degrees and a rather gusty 16 mph wind from the west. You'll find excellent riding conditions right now in the backcountry. The snow is soft and Utah-like all over except at upper elevations where there are buried stiff wind slabs that are undetectable until you are on them.

Rime, caused by moisture from the air refreezing onto the windward side of these aspen branches. (Pagnocco 2-5-2016)
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
  • No new avalanches were reported in the Logan Zone in the last few days...
  • 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

West wind increased a bit overnight drifting the fresh light snow in exposed terrain, and you are likely to trigger fresh wind slab avalanches on some steep drifted slopes at upper elevations.

  • Avoid fresh and forming drifts in deposition zones near ridge tops and in and around terrain features like gullies, sub-ridges, scoops, and rock outcroppings.
  • I expect these wind slabs will be a bit stiffer and deeper than yesterday, but still probably 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. Deep 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 many of my snowpit tests in shallower snow, but the results are less consistent.
Avalanche Problem 3
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 12 hours
description

As the fresh powder is warmed by direct sun or possible greenhousing today, it'll become moist and may be prone to sluffing on steep slopes. Natural loose wet avalanches may become likely if temperatures rise rapidly, and avalanches might be initiated by snow falling off rocks or trees onto steep slopes below. Roller balls or shallow sluffs indicate the potential and increasing danger of wet avalanches. Loose wet sluffs could gouge down and include significant snow in descent. If the snow you're in starts to become sticky and moist you should avoid steep slopes and head to somewhere less steep or more shady.

weather

Expect a warming trend and increasingly fair weather in the mountains as a strong high pressure system begins to build into the region. It'll be partly sunny in the mountains today, with a high temperature at 8500' of around 31 degrees and 15 to 20 mph westerly winds on the ridges. Winds will shift from the northwest and increase a little tonight and it'll be mostly cloudy with a low temperature of around 18 degrees. It'll be mostly sunny tomorrow, with a high temperature around 31 degrees... Looks like the high will only gain strength as we head into next week and the weather will be nice, sunny, and mild in the mountains while the dreaded smog and haze builds in the valleys.
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.