Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Sunday - February 25, 2018 - 6:47am
bottom line

The danger is CONSIDERABLE on drifted upper elevation slopes. Drifting from increasing southwest wind is causing dangerous wind slab avalanche conditions, and the danger will rise and become more widespread during the day. 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.




special announcement

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.
current conditions

Recent cold temperatures preserved the nice powder from last week, and several more inches of very light fresh snow fell overnight. The problem is, westerly winds picked up yesterday afternoon and will continue to intensify today. 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' reports 8 inches of new snow, mostly overnight, containing 0.7" SWE ​(or Snow Water Equivalent). It's 8°F and there is 78 inches of total snow, with 86% of normal SWE.
  • It's 9°F at the UDOT Hwy 89 Logan Summit sheds, and westerly winds increased overnight and are currently blowing 15 mph, with gusts approaching 30 mph.
recent activity
  • A party of riders remote triggered a 300' wide avalanche from the ridge on an east facing slope at around 9000' in elevation near Gibson Basin on Monday, 2/19. Nobody got caught. The avalanche stepped down into old (faceted) layers.

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. Southwesterly winds are already cranking along the ridges this morning and will increase further today.

  • Watch for and avoid drifted snow in and around terrain features like cliff bands, gullies, scoops, and sub-ridges.
  • Wind slabs could rapidly form with even moderate winds on the lee side of major ridges 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.
  • Avoid ridge-top cornices, which often break further back than expected and can trigger avalanches on drifted slopes below.

A party reported cracking indicating reactive wind slabs, 12" to 16" deep in the Bloomington Canyon Area in southeast Idaho, west of Bear Lake.
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

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.

  • Wind slabs formed and are building on slopes with poor snow structure, and dangerous avalanches failing on persistent weak layers are possible.
  • Continue to avoid steep rocky slopes with shallow snow cover and poor snow structure.
  • Avalanches could be remote triggered, from a distance or below.
  • Cracking and collapsing or whumpfing are red flags indicating unstable snow.
weather

The upper level trough over eastern Utah will exit the state early this morning, The next upper trough will settle into California early in the week, then turn east and impact mainly southern Utah midweek. A significant storm system could impact much of the Great Basin late in the week.

  • Today: A chance of snow before 11am, then a chance of snow showers after 11am. Mostly cloudy, with a high near 18. Wind chill values as low as -19. Windy, with a southwest wind 25 to 30 mph increasing to 33 to 38 mph in the afternoon. Winds could gust as high as 55 mph. Chance of precipitation is 50%. Total daytime snow accumulation of 1 to 3 inches possible.
  • Tonight: Snow likely, mainly after 11pm. Cloudy, with a temperature falling to near 12 by 8pm, then rising to around 19 during the remainder of the night. Wind chill values as low as -10. Windy, with a southwest wind 30 to 34 mph, with gusts as high as 48 mph. Chance of precipitation is 70%. New snow accumulation of 3 to 7 inches possible.
  • Monday: Snow. High near 24. Wind chill values as low as zero. Windy, with a southwest wind 21 to 26 mph increasing to 29 to 34 mph in the morning. Winds could gust as high as 48 mph. Chance of precipitation is 80%. New snow accumulation of 4 to 8 inches possible.
general announcements

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.

Benefit the Utah Avalanche Center when you buy or sell on eBay - set the Utah Avalanche Center as a favorite non-profit in your eBay account here and click on eBay gives when you buy or sell. You can choose to have your seller fees donated to the UAC, which doesn't cost you a penny Check it out on ITunes, Stitcher, the UAC blog, or wherever you get your podcasts.

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.