Avalanche forecast

Salt Lake

Issued Feb 5, 2020valid to Feb 6, 2020Utah Avalanche Center

Avalanche danger

Alpine
Treeline
Below treeline

Out of date — this forecast expired 7 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Today a MODERATE danger exists on all upper elevation aspects and west, south, and east-facing mid-elevation slopes where fresh slabs of wind drifted snow exist.

Shallow soft slabs and sluffing remains possible in the new snow on steep slopes at the mid and upper elevations.

A LOW avalanche danger is found on north-facing mid-elevation slopes and all slopes under 8,000' in elevation where generally safe avalanche conditions exist.

Heads up: A warm, wet, and windy storm will rapidly raise the avalanche hazard over the next few days.

Avalanche problems

Wind Slabs
N
NE
E
SE
S
SW
W
NW
Alpine
Treeline
Below treeline
Likelihood
Possible
Size
2
Since Monday plenty of light snow of varying depths is available for winds to transport. Winds have been strong enough to create sensitive wind drifts and these winds will steadily increase throughout the day. As the winds continue to increase, these wind drifts will become more widespread.

Winds have been primarily northerly for the last 24 hours and should continue to be northwesterly into the evening. Today, I would expect to find sensitive slabs of wind drifted snow at all upper elevation slopes and west, east and south-facing mid-elevation slopes, especially along with terrain features such as ridgelines, sub ridges, and gullies.

Look for slopes with any signs of wind drifted snow, such as cracking, hollow noises, and pillow-shaped snow and avoid those slopes.
Storm Slabs
N
NE
E
SE
S
SW
W
NW
Alpine
Treeline
Below treeline
Likelihood
Possible
Size
2
On Monday 4-18 inches of low-density snow fell on a variety of smooth surfaces. The new snow has been reported to be running far and fast in steep terrain. In protected areas that got higher snowfall and have not yet been affected by the wind, I would still expect shallow soft slab and small point release avalanches in this new snow.

Be especially thoughtful of this while traveling above terrain traps, cliff bands and features which the debris could pile up.

Photo of a long-running sluff in Bowman Fork yesterday. (Photo: M. White)

The good news: These can be well managed through avoidance, think about what is above and below you, and with ski cuts.

Special Announcement

Discounted lift tickets - Thanks to the generous support of our Utah ski resorts and Ski Utah, all proceeds from these ticket sales go towards paying for avalanche forecasting and education! Get your tickets here.

Recent Activity

Yesterday three avalanches were reported, some of which occurred Monday evening. These were shallow soft slabs of new snow, or wind drifted snow. One of these avalanches was a soft slab of new snow on the Memorials on Mt. Olympus, on a northeast aspect at 8,200 feet. This was a soft slab avalanche that failed 2 feet deep on the new snow old snow interface, comprised of a firm old crust. This avalanche ran 250 feet long and 50 feet wide. This avalanche was believed to happen sometime Monday night, into Tuesday morning.

Another avalanche which occurred sometime Monday night, into Tuesday morning as a slab of wind drifted snow in the Brighton Back Bowls on a North aspect at 12,300 feet. This avalanche failed on the new snow/old snow interface. This avalanche ran 150 feet wide and 350 feet wide.

Photo of the slab of wind drifted snow from the Brighton Back Bowls. (Photo: B)

The only avalanche in the backcountry reported to occur yesterday, was a skier triggered soft slab of wind drifted snow in Toledo Bowl, on a southeast aspect at 9,500 feet. This avalanche failed 4 inches deep on the new snow old snow interface and ran 15 feet wide.

Below is a photo of the crown in Toledo Bowl. See full observation HERE. (Photo: C. Hussey)

Across the board there were reports of shallow, far running sluffs in areas of low-density snow that have not been affected by the wind drifts yet.

Minor sluffing and an occasional shallow wind drift triggered by ski area control teams.

Snow and Weather

Mountain temperatures are still cold! Trailhead temperatures are currently hovering above 0 F, while the uppermost ridgetops near 11,000 feet are just above -10 F. Winds are currently northwesterly averaging between 15-20 mph, with gusts above 25 mph. The uppermost ridgetops are gusting up to 45 mph.

Today, temperatures will remain cold averaging in the low teens F. Winds should remain northwesterly with a few gusts up to 45 mph, and increasing throughout the day into the evening. Skies will be partly cloudy until snow lightly begins this afternoon and picks up around midnight.

Looking forward, we have a storm on the horizon that could bring up to 2 feet of heavy, warm snow in combination with moderate to strong winds. Below is the briefing from the National Weather Service.

Additional Info

This afternoon we have another system moving through. It is predicted to start cold, and transition to a heavy, warm, wet snowfall. This is known as an upside-down storm, which occurs when a storm deposits denser snow over less dense snow, in turn rapidly creating a slab/weak layer combination.

In our situation, this warm heavy snow is going to fall on the light, low-density snow from Monday. Following Monday, we have had two days of cold temperatures, which will have just further weakened the new snow. Cold temperatures are what drive faceting, one of the fundamental processes to a weak layer. As the snow totals begin to increase this evening and into tomorrow morning the avalanche danger will rapidly be on the rise.

Tree-well immersions and asphyxiation should be on the radar in areas that received the most snow. Frost-bite is of concern. Roof-alanches should also be on the radar in the coming days as the temperatures increase.

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