Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Monday - February 19, 2018 - 6:43am
bottom line

Dangerous avalanche conditions exist in the backcountry. The danger is CONSIDERABLE, human triggered avalanches are likely, and natural storm slab and wind slab avalanches are possible. Drifting from increasing northwest wind could cause the danger to rise to HIGH on some upper elevation slopes.

  • Stay off and out from under steep slopes with deep fresh powder, and especially those with drifted new snow.
  • There is less danger in sheltered, lower angled, and lower elevation terrain.
  • Evaluate snow and terrain carefully, and make conservative decisions.




current conditions
  • Beaver Mountain reports 10°F and calm conditions, with 19 inches of fresh powder in the past 24 hrs, which mostly fell during the day yesterday.
  • The Tony Grove Snotel at 8400' reports 16 inches of settled new snow from yesterday's storm, with 1.6" SWE (or Snow Water Equivalent). At 2:00 this morning the station reported 15°F, and 76 inches of total snow, with 87% of normal SWE
  • I'm reading 15°F at the UDOT Hwy 89 Logan Summit sheds, and a light west-northwest breeze is blowing 4 mph

recent activity
  • There were several natural avalanches that occurred at upper elevations during periods of heavy snow and strong wind Thursday and more on Friday.
  • Snowboarders unintentionally triggered, but escaped a slow moving soft slab avalanche in Miller Bowl above Tony Grove Lake Thursday, 2/15.
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
  • Human triggered soft slab avalanches up to about 2 feet deep are likely at upper and mid elevations.
  • Loose avalanches entraining the new snow and running on a slick ice-crust are also possible in steep terrain. Be aware of possible terrain traps, like trees, cliffs, or benches below you.
  • The weight of the storm snow could be enough to reawaken dormant buried faceted layers, and dangerous persistent slab avalanches are possible. Continue to avoid steep rocky slopes with shallow snow cover and poor snow structure.
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

Northwest wind will have plenty of soft powder snow to drift, and it will rapidly create new wind slabs in avalanche starting zones. Dangerous avalanche conditions exist in drifted terrain. There is a good chance that northwest winds will increase more than forecast, and a HIGH danger could develop on drifted upper elevation slopes, with natural wind slab avalanches avalanches becoming likely.

  • Wind slabs are made up of stiffer, drifted snow. They can appear chalky and rounded and can make hollow drum-like sounds.
  • Avoid drifted snow in and around terrain features like sub-ridges, cliff bands, scoops, and gullies.
  • Avoid ridge-top cornices, which often break further back than expected. Wind slab avalanches are likely today under cornices.
  • In some areas, wind slabs are forming on slopes with poor snow structure, and dangerous avalanches failing on persistent weak layers are possible.
  • Cracking and collapsing or whumpfing are red flags indicating unstable snow.

Westerly winds picked up Saturday afternoon, drifting snow at upper elevations in the Wellsville Range


weather

A winter storm will impact much of Utah through early Tuesday. Another weather disturbance is possible late in the week.

  • Washington's Birthday: Snow. High near 16. Wind chill values as low as -8. North wind 11 to 20 mph. Chance of precipitation is 80%. Total daytime snow accumulation of 1 to 2 inches possible.
  • Tonight: Snow likely before midnight, then snow showers after midnight. Low around 0. Wind chill values as low as -13. West northwest wind 9 to 14 mph. Chance of precipitation is 80%. New snow accumulation of less than a half inch possible.
  • Tuesday: Snow showers likely, mainly before noon. Cloudy and cold, with a high near 10. Wind chill values as low as -13. West wind 7 to 9 mph. Chance of precipitation is 60%. New snow accumulation of less than a half inch 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.

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.

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.