AVALANCHE WARNING!! Tap for info

Forecast for the Salt Lake Area Mountains

Greg Gagne
Issued by Greg Gagne on
Friday morning, January 24, 2020
The avalanche hazard is generally Low, but a MODERATE avalanche danger exists on upper elevation slopes with wind drifted snow where there remains a chance for triggering a shallow soft slab avalanche. Although unlikely, there is also a chance for triggering a deeper avalanche on upper elevation slopes facing west, through south, and east.
Low
Moderate
Considerable
High
Extreme
Learn how to read the forecast here
Special Announcements
We are very sad to report an avalanche fatality from Saturday above Farmington Canyon. An 18-year-old male snowmobiler was caught, fully buried and killed. The final report is available HERE. Our deepest condolences go out to the friends, family, rescuers, and everyone affected by this tragic accident.

Join Drew Hardesty at the new Black Diamond Store at Trolley Square at 7PM on January 27 for a Fireside Chat on Expert Intuition and the Avalanche Problem.
Weather and Snow
Currently: Mountain temperatures are a few degrees on either side of 20 F and winds are out of the west/southwest and very light, < 10 mph, with gusts in the teens along the upper-most ridgelines. The mountains received another 1-3" of dense snowfall Thursday morning, with riming at the surface noted in some places. Since Tuesday, snowfall amounts are 14-18" (containing 1.5 - 2.24" water) in the upper Cottonwoods and about 8" (containing 0.7" water) along the Park City ridgeline.
For Today: Increasing clouds with light snow possible this afternoon. We'll likely squeeze a few inches out of this system. Winds will be out of the west/southwest and remain light, with gusts in the teens at the upper-most elevations. Temperatures will remain mild, rising above freezing to about 8500', and in the 20's above that.
This weekend: Dirty ridging in place with periods of mid and high clouds. Winds will remain light and temperatures mild, generally in the 20's. Another weak system expected later on Sunday.

Our Week in Review which summarizes significant avalanche and weather events from this past week has been published. Click HERE.
Recent Avalanches
Control work at resorts reported small soft slabs and dense wind drifts. In the backcountry, most observers noted instabilities of storm snow and wind drifts had largely settled out, but a few slides were reported including a 60' wide and 2' deep soft slab in upper Dry Fork (Observation) (pic: Jessie W)
Other avalanches in wind-drifted snow included Tuscarora (observation) and the South Face of Mount Superior (observation), the latter which may have run several hundred feet.
Warm temperatures yesterday led to damp snow with some wet roller balls below about 8,000'
Click here to read all observations for the Salt Lake area mountains.
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Avalanche Problem #1
Wind Drifted Snow
Type
Location
Likelihood
Size
Description
Yesterday I was finding instabilities with storm and wind-drifted snow to have largely settled out, but control work at resorts and a few backcountry observations indicated avalanching in recent wind drifts is still possible. You can find areas of wind-drifted snow on all aspects at the upper elevations. These drifts can be 6-18" thick, and run long distances if they are sitting on top of a firm wind or temperature crust. Watch for signs of recent wind drifts including dense slabs or rounded pillows of snow. Although ski cuts are an effective tool for mitigating this hazard, be sure no one is below you before ski cutting a slope.

Additionally, strong winds Tuesday and Wednesday added heft to existing cornices. These large cornices often break much further back than expected, so be sure to give them a wide berth when traveling along the exposed ridgelines.
Avalanche Problem #2
Persistent Weak Layer
Type
Location
Likelihood
Size
Description
A buried thin sun and temperature crust exists on some slopes facing west, through south, and east where there is a persistent weak layer of faceted snow and above and below this crust. During the first week of January, at least nine avalanches were reported on these aspects, failing in faceted snow above and below this crust. Field observations (and a lack of subsequent avalanching on this weakness) indicated this weak layer had gained strength. But on Sunday a very large avalanche (up to 500' wide) was triggered by a skier in Mill B South in Big Cottonwood Canyon (observation). An outlier? Probably. Especially when we see many other steep south-facing lines being skied without incident. Although triggering an avalanche on this layer is unlikely, the consequences are significant.
What to do? Well, you can pull out your shovel and dig down 1-3' deeply where you will look for a crust. You will then need to assess the strength of the weak layer(s) near this crust and the propensity of the slab above to propagate by performing an extended column test (ECT). A fracture propagating across the entire column indicates a dangerous structure and the slope should be avoided. And remember, one pit only provides one data point - you will need to assess the slope at several different locations. Sound complicated? Simply avoid the problem by turning to northerly aspects where this problem doesn't exist.

More thoughts on why to dig can be found below under "Additional Information"
Additional Information
Why dig and perform an extended column test (ECT)? Several reasons: (1) It helps you make informed decisions when traveling in avalanche terrain. (2) It forces you to slow down and discuss what is going on in the snowpack. (3) I consider digging a snowpit to be rescue practice because I become more proficient at digging in the snow and using my shovel.
General Announcements
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.