Avalanche forecast

Salt Lake

Issued Dec 6, 2022valid to Dec 7, 2022Utah Avalanche Center

Avalanche danger

Alpine
Treeline
Below treeline

Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

A tricky CONSIDERABLE avalanche danger exists on steep west to north to southeast facing slopes at the mid and upper elevations. Dangerous human triggered avalanches 1-4' deep and up to 300' wide are likely...and may be triggered at a distance. A MODERATE avalanche danger exists on all south and southwest facing slopes and in the low elevation bands.

NOTE that loose new snow avalanches can be expected in very steep terrain of all aspects again today.

Travel Advice: Choose low angle terrain with nothing steep above.

Avalanche problems

Persistent Slabs
N
NE
E
SE
S
SW
W
NW
Alpine
Treeline
Below treeline
Likelihood
Likely
Size
3
The mid-November drought created a very weak snow surface composed of facets and patches of surface hoar on all aspects and elevations throughout the Wasatch Range. Avalanches have been triggered at this weak interface nearly every day since November 29th. North and East facing aspects harbored some of the weaker faceted snow and have also seen the most wind loading (primarily last Wednesday and Thursday). Not surprisingly, the bulk of the natural and human triggered avalanches have occurred on these aspects (see Heat Map of avalanches below).

These soft and hard slab avalanches are failing on this weak PWL (persistent weak layer) 1-4' deep and up to 350' wide. These avalanches are sometimes accompanied by audible whumphs or collapses...with many of them triggered at a distance.

November's low sun angle and colder than normal temperatures led to a poor snowpack structure on south and west facing aspects and backcountry observers have experienced cracking and collapsing in this terrain. This is unusual. Although these "off aspects" have a more complicated snow structure and have experienced less loading (in fact some scouring away of snow), I am not ready to trust these aspects just yet.

TREND: STEADY

Special Announcement

Join the Utah Avalanche Center and the Division of Outdoor Recreation to celebrate the Fourth Annual Avalanche Awareness week, from December 4 - December 11. Click here to view the full list of events for the week. A few of note below:

Recent Activity

Two more remotely triggered avalanches reported along the Park City ridgeline yesterday, each running on the PWL (persistent weak layer) of weak sugary facets.

No No Name - 9700' East facing 2-3' deep 300' wide, triggered from 200' away (1st photo, Nalli)

No Name shoulder - 9200' NE facing 2' deep 50' wide, triggered from 100' away. (2nd photo, Nalli)

(Uncertain of locations? Check out the Wasatch Backcountry Skiing map...or app on your phone)

Some natural and human triggered loose snow sluffing also noted in the new snow.

Snow and Weather

Skies are clear.

Storm totals are 10-16" in the upper Cottonwoods and along the Park City ridgeline. Densities are the stuff of dreams - 4-5% of cold smoke fell yesterday and made for some of the best skiing and riding of the year on all aspects and elevations.

As of 5am, mountain temperatures are in the single digits and low teens. Winds are light and westerly.

For today we'll have mostly clear skies, light west to southwest winds and temperatures in the mid-teens up high, the low twenties down low. Should be glorious.

The Outlook: We'll have good powder preservation weather through the week with generally cool temps and light winds. A weak system pushes through mid-week that'll bring a few inches to the central Utah mountains and possibly as far north as the Provo area mountains. Beyond that, the models depict another storm for the weekend.

Mark Staples put together a comprehensive Weather and Snow Summary HERE>

Additional Info

MOST ACCIDENTS AND FATALITIES OCCUR DURING A CONSIDERABLE AVALANCHE DANGER THAT INVOLVES A PERSISTENT WEAK LAYER.

A word to the wise: Don't get fooled.

As avalanches become more stubborn and cracking and cracking become less commonplace, there can be a tendency to believe that conditions are improving faster than they are.

The GOOD NEWS is that riding conditions are 5 STAR on all aspects and on low angle slopes. Choose low angle terrain with nothing steep above you.

General Announcements

CLICK HERE FOR MORE GENERAL INFO AND FAQ

This information does not apply to developed ski areas or highways where avalanche control is normally done. This forecast is from the U.S.D.A. Forest Service, which is solely responsible for its content. This forecast describes general avalanche conditions and local variations always occur.

Observations and Avalanches

Backcountry Emergency Procedures