Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Wednesday - January 31, 2018 - 6:22am
bottom line

Heightened avalanche conditions exist in the backcountry. Dangerous human-triggered persistent slab avalanches are gradually becoming less likely, but remain possible on steep slopes with poor snow structure.

  • Evaluate snow and terrain carefully.

I will update this advisory on Friday, 2/2/18, before about 7:30 AM.




special announcement

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.

current conditions

Unseasonably warm weather has taken toll in the Logan Zone. Last week's snow covered trails are now blue water ice, and many low elevation slopes melted off and are now bare. It rained Saturday night and there's a thick and brittle translucent ice-crust on the snow surface at upper and mid elevations across the zone, capping last week's nice powder like creme brulee. The Tony Grove Snotel at 8400' reports 30°F, and there's 57 inches of total snow at the site containing 89% of normal SWE (or Snow Water Equivalent). It's also 30°F at UDOT Hwy 89 Logan Summit and a northwest wind is blowing around 20 mph with gusts in the 30s this morning. Heightened avalanche conditions exist on slopes plagued by poor snow structure, and dangerous human triggered persistent slab avalanches remain possible.



A rime (icing) event occurred Saturday night, capping all the nice powder with a creme brulee ice-crust.

recent activity

No avalanches were reported recently in the Logan Zone.

A skier was caught carried by an avalanche in Big Cottonwood Canyon in the Wasatch Range on Sunday, 1/28/18. View Report , and Here's the video:

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

Dangerous triggered persistent slab avalanches remain possible on steep slopes, especially those with shallow snow and poor snow structure. Widespread faceted layers appear dormant currently, but a new load from the recent storm and slab softening due to warmth may reactivate buried weak layers in some areas, especially on previously drifted slopes.

  • Some drifts likely formed in areas with poor snow structure last week, overloading weak faceted snow, and dangerous persistent slab avalanches involving previously drifted snow are possible.
  • Pay attention to possible signs of instability like cracking and whumpfing or collapsing, but remember these signs aren't always present when avalanches are triggered, so you have to dig down into the snow to find poor snow structure.
  • Persistent slab avalanches are often triggered from low on the slope, and might be triggered remotely, from a distance or below.‚Äč

Mark found a buried layer of surface hoar in the Monte Cristo Area on Monday. This also exists in some areas in the Logan Zone

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

Despite an incessant strong west wind, the widespread rime or rain crust is holding snow in place and preventing drifting in most areas. There may be some areas where the crust did not form and drifting is occurring. In areas where drifts have formed recently, you could trigger small wind slab avalanches.

  • Watch for and avoid drifted snow on steep lee slopes and in and around terrain features like sub-ridges, gullies, scoops, and rock outcrops.
weather

A dry cold front will cross the area today. High pressure will strengthen again along the West Coast late in the week allowing a couple of weak weather disturbances expected to cross northern Utah through Saturday.

  • Today: Mostly cloudy, with a high near 29. Breezy, with a west wind 22 to 26 mph, with gusts as high as 40 mph.
  • Tonight: A 20 percent chance of snow after 11pm. Mostly cloudy, with a low around 21. Breezy, with a west wind 22 to 24 mph, with gusts as high as 38 mph.
  • Thursday: A 40 percent chance of snow. Mostly cloudy, with a high near 33. Breezy, with a west wind 14 to 22 mph. New snow accumulation of 1 to 3 inches 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 these go towards paying for avalanche forecasting and education!

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

Episode 3 of the UAC podcast is live. We talk with UDOT Avalanche Program Supervisor Bill Nalli on how he and his teams keep the Greatest Snow on Earth from avalanching over the open roads and highways of the state. 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.

EMAIL ADVISORY: If you would like to get the daily advisory by email you will need to subscribe here.

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 tweet or 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.