Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Monday - February 26, 2018 - 7:04am
bottom line

Drifting from strong southwest wind has created dangerous wind slab avalanche conditions in the backcountry. A CONSIDERABLE danger exists on drifted upper elevation slopes. You'll find excellent Utah powder riding and safer conditions in sheltered, lower angled, and lower elevation terrain.

  • Evaluate snow and terrain carefully, and make conservative decisions.
  • Avoid and stay out from under steep drifted slopes.




current conditions

Recent cold temperatures preserved the nice powder from last week, and another 10" or so fell over the weekend. Several more inches of snow is expected to fall in the mountains today. Strong southwest winds are a problem. The light powder is easily picked up and drifted into lee slope deposition areas and upper elevation avalanche starting zones. You'll find excellent backcountry powder riding and skiing in sheltered, lower angled, and lower elevation terrain, but use a heightened degree of situational awareness because human-triggered avalanches are likely on drifted upper elevation slopes.

  • The Tony Grove Snotel at 8400' reported 76 inches of total snow, with 86% of normal SWE as of 8:00 PM last night.
  • It's 18°F at the UDOT Hwy 89 Logan Summit sheds, and northwesterly winds are currently blowing around 10 mph.
recent activity

Yesterday's increase in westerly wind caused natural cornice fall avalanche activity, and we have reports of a few intentionally triggered wind slabs in drifted terrain.
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

The recent fresh powder is so light it is easily drifted into avalanche starting zones. Human triggered wind slab avalanches are likely today in drifted terrain.

  • Watch for and avoid drifted snow in and around terrain features like cliff bands, gullies, scoops, and sub-ridges.
  • Wind slabs will be found today on the lee side of major ridges, on slope below cornices, and downwind of open fetch areas.
  • Drifts are forming on slopes with poor snow structure, and some wind slab avalanches could step down to buried weak faceted layers.

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

Avoid ridge-top cornices, which often break further back than expected and can trigger avalanches on drifted slopes below.


A natural cornice-fall triggered avalanche hit Tony Grove Lake with soft debris on Sunday, 2/25.
Avalanche Problem 3
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 24 hours
description

Areas with heightened persistent slab avalanche conditions exist at upper and mid elevations, mainly in drifted terrain. Dangerous human triggered avalanches stepping down into buried persistent weak layers are possible.

  • Continue to avoid steep rocky slopes with shallow snow cover and poor snow structure.
  • Avalanches might be remote triggered, from a distance or below.
  • Cracking and collapsing or whumpfing are red flags indicating unstable snow.
weather

A developing upper level low pressure system over California later today will eventually turn east and track across Arizona midweek. Precipitation on the periphery of this low pressure system will impact northern Utah through Tuesday, then southern Utah midweek. A significant winter storm will reach the Great Basin for late in the week through the upcoming weekend.

  • Today: Snow. High near 23. Wind chill values as low as -3. Windy, with a southwest wind 26 to 31 mph, with gusts as high as 45 mph. Chance of precipitation is 80%. Total daytime snow accumulation of 3 to 7 inches possible.
  • Tonight: Snow likely. Cloudy, with a low around 15. West wind 11 to 17 mph becoming northeast after midnight. Chance of precipitation is 70%. New snow accumulation of 2 to 4 inches possible.
  • Tuesday: A chance of snow before noon, then a slight chance of snow showers after noon. Mostly cloudy, with a high near 24. Wind chill values as low as zero. East northeast wind 13 to 15 mph becoming west northwest in the afternoon. Chance of precipitation is 30%. New snow accumulation of less than a half inch possible.
general announcements

We have discount lift tickets for Alta, Snowbird, Brighton, Solitude, Snowbasin,and Beaver Mountain. Details and order information here. All proceeds from your purchase go towards paying for avalanche forecasting and education.

Episode 5 of the UAC podcast To Hell in a Heartbeat - A Conversation With Tom Diegel and Matt Clevenger About the 12.26.08 Full Burial on Little Water is live. This podcast talks with Matt and Tom about their experience and the massive success of the To Hell in a Heartbeat video which has been viewed almost 3M times. Check it out on ITunes, Stitcher, the UAC blog, or wherever you get your podcasts.

The UAC Marketplace is online. The holiday auction is closed, but our online marketplace still has deals on skis, packs, airbag packs, beacons, snowshoes, soft goods and much more.

The UAC has new support programs with Outdoor Research and Darn Tough. Support the UAC through your daily shopping. When you shop at Smith's, or online at Outdoor Research, REI, Backcountry.com, Darn Tough, Patagonia, NRS, Amazon, eBay a portion of your purchase will be donated to the FUAC. See our Donate Page for more details on how you can support the UAC when you shop.

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Now is a great time to practice companion rescue techniques with your backcountry partners. Here's our rescue practice video.

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Remember your information can save lives. If you see anything we should know about, please help us out by submitting snow and avalanche observations. You can also call us at 801-524-5304, email by clicking HERE, or include #utavy in your Instagram.

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 occur.