Avalanche forecast

Salt Lake

Issued Mar 20, 2021valid to Mar 21, 2021Utah Avalanche Center

Avalanche danger

Alpine
Treeline
Below treeline

Out of date — this forecast expired 5 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

This morning the overall avalanche danger is LOW rising to MODERATE as the storm develops, but it may spike to CONSIDERABLE during periods of heavy snowfall late this morning and early this afternoon. Today's new snow may produce soft slab avalanches or long-running sluffs. Additionally, the elevated winds may create unstable slabs of wind-drifted snow at mid and upper elevations. Pay attention to changing weather patterns. Human-triggered avalanches are possible. Natural avalanches are unlikely, but possible during periods of heavy snowfall rates (exceeding 2" an hour) or stronger winds.

Avalanche problems

Wind Slabs
N
NE
E
SE
S
SW
W
NW
Alpine
Treeline
Below treeline
Likelihood
Possible
Size
2
This morning the winds are cranking, with gusts near 60 mph and expected to increase to 75 mph. These high southwesterly winds may create fresh wind drifts on any aspect at the mid and upper elevations. These wind drifts will be generally shallow and isolated to terrain features that allow for drifting new snow to accumulate, such as ridges, sub-ridges and gullies.

Look for obvious signs of wind-drifted snow, such as pillow-shaped slopes, cracking and whumpfing, and avoid those slopes.
Storm Slabs
N
NE
E
SE
S
SW
W
NW
Alpine
Treeline
Below treeline
Likelihood
Likely
Size
1
The issue is simple today, as the snowfall intensity increases, the avalanche danger is going to increase as well. The cold front moving in this morning is predicted to have periods of very high snowfall rates, as well as overall high snowfall totals (10-16" of snow by Sunday). All of this new snow is going to have a variety of excellent bed surfaces to slide on and once the snowfall begins, I expect to see shallow new snow avalanches in the backcountry today.

With the generally warm temperatures, I expect the new snow to be fairly cohesive and should break as a shallow soft slab, but, with so many supportable bed surfaces, fast running sluffs are also likely today, especially in the upper elevations. The type of avalanche will come down to how quickly the new snow bonds, versus how quickly the snow is falling from the sky. Watch for signs of instability such as cracking and sluffing. Even a small slide can have serious consequences in big, steep terrain or if you’re above cliffs.

Today, the sensitivity of the new snow largely depends on the rate of snowfall. During higher rates of snowfall (greater than 1 inch per hour) avalanches will be easier to trigger. Periods of snowfall exceeding 2 inches per hour are possible during the day today, especially late this morning and early afternoon. During those periods of high snowfall rates, small natural avalanches may be possible. Pay attention to changing weather and increased snowfall rates.

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Recent Activity

Only minimal avalanche activity was reported from Friday, including minor wet-loose activity.

Our Week in Review - where we highlight significant snow and avalanche activity from this past week has been published.

Snow and Weather

This morning, Skies are broken and temperatures are in the upper 20's and low 30's F. Winds are primarily from the south and gusty. At mid-elevations winds are averaging in the twenties with gusts in the 40s to 50s mph. At the upper elevations, winds are averaging in the 30s with gusts in the 50s and 60s mph.

Today, a winter weather advisory goes into effect this morning at 6AM. A cold front will cross northern Utah this morning into early afternoon, and this will bring strong winds and heavy snowfall. Temperatures will be in the mid and upper 30s F. Winds will stay elevated throughout the day, with peak gusts this morning up to 75 mph at upper elevations and 50 mph at mid elevations. Snowfall totals today should be between 8-12" before 6PM this evening.

The strongest snowfall of the day will come late morning into the early afternoon, where snowfall rates could be above 2" an hour. The storm totals could bring us 10-16 inches of snow, and up to 1.50” inches of water by tomorrow evening.

Weather story from the National Weather Service - Find full Winter Weather Advisory HERE.

General Announcements

Please visit this website with information about Responsible Winter Recreation by the Utah Office of Outdoor Recreation.

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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