Avalanche Advisory
Advisory: Salt Lake Area Mountains Issued by Evelyn Lees for Monday - January 22, 2018 - 6:43am
bottom line

The Avalanche Danger is MODERATE on steep, mid and upper elevation slopes facing northerly through easterly. Human triggered avalanches are possible, and large, dangerous avalanches can be triggered in isolated places. Use a slope inclinometer and compass to identify and avoid the steep, north through easterly facing slopes, where it’s most likely to trigger an avalanche.

Today’s increasing southwesterly winds will also create a MODERATE danger for triggering wind drifts along ridge lines.

Low angle slopes of all aspects have superb turning and riding in classic Utah powder.
special announcement

Episode 3 of the UAC podcast went live last night. 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. Find it on our blog site (linked above), iTunes, Stitcher, or wherever you get your podcasts.

Do you know the parable of the Scorpion and the Frog? A short piece of fiction from Mineral Fork here.

current conditions

It’s going to be another powder preserving day, with increasing clouds, cold temperatures and light winds. Under mostly clear skies, temperatures are in the single digits this morning. Winds are from the southwest, averaging less than 5 mph at the low and mid elevations. The higher ridge lines and peaks have wind speeds of 15 to 20 mph, with gusts to 30 mph.

The weekend storm delivered - fairly even storm totals of 15 to 23” of superb, low-density powder at both mid and upper elevations. Cloudy skies yesterday kept the snow soft on all aspects.

recent activity

Sunday reported avalanche activity:

  • A slide triggered on a northeast facing slope at 9800’ in Caribou Basin was a 100’ wide, and looks like it stepped into a deeper weak layer in the center.
  • A new wind slab was triggered along the Patsey Marly ridge line, about 100 feet wide by 18” deep, long running.
  • In the Ogden area mountains, 2 skiers were caught in an avalanche at Snowbasin. A serious slide, but the outcome was good - though one person was buried, they were recovered quickly and OK. The second person also took a ride, but ended up on top with only minor injuries.

Top photo - Caribou slide, Ross photo Lower photo - Patsey Marly ridge line wind slab, Sean Burkhart photo


Click HERE for a list of all reported avalanches in Utah.
Avalanche Problem 1
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 12 hours
description

The unpredictable, multiple layers of buried faceted snow are a serious problem – they were the weak layer of at least 5 human triggered slides in northern Utah over the weekend - two yesterday and 3 on Saturday - and are the likely culprit of the two weekend fatalities in the west.

Slides in Utah are averaging 2 to 3 feet deep, and over 100 feet wide. The layers of weak, sugary facets they are failing on are notoriously tricky, and the snowpack’s response to the weight of a person is erratic and variable. But the location of the slides are not random – the have been triggered on steep, shady slopes facing northwest through easterly, at the mid and upper elevations, and avoiding those slopes is the best way to avoid triggering an avalanche in the backcountry. Avalanches can still be triggered remotely and from below.

With the weekend refill of perfect powder, lower angle slopes of all aspects once again have excellent riding and turning conditions.
Avalanche Problem 2
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 12 hours
description

There are enormous amounts of snow available for transport, and even wind speeds as low as 15 mph quickly move low density snow into drifts. Along both the Salt Lake and Park City area ridge lines, snow will be moving today and forming soft drifts. These can be triggered on steep slopes, and will be most widespread on north through easterly facing slopes. The drifts should be mostly confined to right along the ridge lines, but look for drifts anywhere you find the wind blowing.
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

Fast moving sluffs can be triggered on steep slopes of all aspects, far running where they are on slick underlying sun and wind crusts, entraining all the storm snow in the path below. They tend to break below a person,

weather

As a weak disturbance scoots by to the north, there will be increasing clouds today and a chance for a few snowflakes near the Idaho border. Temperatures will try to crawl out of the icebox, warming into the teens to mid 20s. The southwesterly winds will average less than 10 mph at most low and mid elevations, but speeds will increase with elevation. Average speeds of 15 to 25 mph, with gusts to 40, will occur above about 10,500’ by afternoon. Temperatures and wind speeds will increase tomorrow ahead of a fast moving storm, which should bring a shot of snow Thursday night.
general announcements

CLICK HERE FOR MORE GENERAL INFO AND FAQ

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This information does not apply to developed ski areas or highways where avalanche control is normally done. 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.