Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Friday - March 4, 2016 - 7:17am
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MODERATE (level 2): The snow is stable on most slopes and avalanches are generally unlikely. However, heightened avalanche conditions exist at upper elevations, primarily in the northern portion of the Logan Zone, with cornice fall, wind slab, and midday loose wet avalanches possible. Use normal caution, but evaluate the snow and terrain carefully, especially in upper elevation areas with fresh accumulations and recent drifting.
current conditions

The Tony Grove Snotel at 8400' reports an inch of new snow and 33 degrees this morning. There's 71 inches of total snow containing 93% of average water for the date. It's 30 degrees and northwest winds continued to diminish overnight at the 9700' CSI Logan Peak weather station, currently showing single digit average wind speeds. Conditions vary widely across the zone, with a few inches of dusty new snow accumulation and significant drifting in the north and reports of good spring "corn snow" yesterday from big east and west facing slopes on both sides of Cache Valley.

We chose to avoid recently drifted upper elevation slopes Wednesday, like this one on the northeast face of Wilderness Peak in the Gibson Lakes Area out of Franklin Basin in Southeast Idaho. (3-2-2016)
recent activity
  • No new avalanches were reported locally since last Friday when riders triggered several small and manageable soft wind slabs on very steep upper elevation slopes, and some natural loose wet slides occurred in sunny terrain. But, I found semi-sensitive cornice yesterday and was easily able to knock off good sized chunks in the backcountry on the south ridge of Beaver Mt.

  • ***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

Heightened wind slab avalanche and cornice fall conditions exist in some upper elevation terrain, mainly in the northern portion of the zone where more fresh snow accumulated this week.

  • Beware large overhanging ridge-top cornices, which could break further back than you expect and might trigger avalanches on drifted slopes below. Natural cornice falls are possible in some areas during the heat of the day. I noticed some of these that are dripping and starting to buckle in the warmth.
  • Wind slabs appear pretty well glued into the terrain, but you could trigger avalanches on some drifted slopes, especially in areas downwind of treeless flats or fetch areas, where sustained winds can gather large quantities of light surface snow. As usual, watch for and avoid recent drifts on the lee sides of ridges, cross-loaded along sub-ridges, and in and around terrain features like rock outcroppings, gullies, scoops, trees, and saddles.
  • Older, hard wind slabs can be like mouse traps, sometimes allowing people to get well out on them before releasing.

Sustained west winds drifted this week's fresh dust-infused accumulations, which were mainly limited to the northern part of the Logan Zone. Here's evidence of the drifting in exposed terrain, the backcountry on the south ridge of Beaver Mt. For you snow nerds and scientists, the new layer of dusty snow will be interesting to watch in the next couple weeks since it'll collect energy from solar radiation even after it's buried. (3-3-2016)
Avalanche Problem 2
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 10 hours
description

Temperatures remained above freezing at most stations overnight. Loose wet avalanches may become possible on slopes where saturated snow is softened by solar warmth.

  • In the northern part of the zone where a few inches of new snow fell this week, sluffs entraining a few inches of warming moist new snow are certainly possible at upper elevations.
  • The snow in the mountains bounding Cache Valley has been through numerous melt-freeze cycles, the round snow grains are fairly large, and avalanches are pretty unlikely even when the snow surface is softened by the midday warmth. Exceptions might be found on steep slopes in shallow or rocky areas with very soft or weak wet snow.
  • You might find decent spring conditions but lacking a good overnight freeze, slopes may become unsupportable with midday warmth, and heightened avalanche conditions will develop on slopes as they soften.

weather

Expect partly sunny conditions today with a high temperature at 8500' around 43 degrees and fairly light westerly wind. It'll be mostly cloudy tonight with temperatures hovering a little above freezing again and pretty calm south winds. It'll be mostly cloudy tomorrow with light south winds and temperatures again in the mid-forties... A Pacific storm will bring snow on Sunday and Sunday night, with 4 to 8 inches of accumulation forecast for upper elevations in the Logan Zone.

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. 

We'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.