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Forecast for the Provo Area Mountains

Nikki Champion
Issued by Nikki Champion on
Wednesday morning, December 28, 2022
The avalanche danger will continue to rise to HIGH on all upper elevation aspects and mid-elevation aspects facing northwest through north and southeast, where strong winds and continued snowfall have created dangerous avalanche conditions. Mid-elevation slopes facing west, southwest, and south and low-elevation slopes facing northwest through north and east have a CONSIDERABLE danger. Any avalanche triggered within the new snow or the wind-drifted snow has the potential to step down into deeper weak layers in the snowpack, creating a very large and dangerous avalanche.
The avalanche danger is MODERATE on the remaining low-elevation slopes that received primarily rain over the last 24 hours.

Traveling on, underneath, or adjacent to slopes steeper than 30° at the mid and upper elevations is not recommended. Avalanche conditions will remain dangerous through the weekend with continued stormy weather.
Low
Moderate
Considerable
High
Extreme
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Special Announcements
Check out this great blog post that Dave put together discussing the persistent weak layer, and the forecaster's current mindset while dealing with it. You can read the full post HERE.
Weather and Snow
This morning, the skies are overcast and snow is lightly falling. Temperatures are in the low 20s to upper-20s F. Westerly winds have backed off overnight, blowing in the mid-20s with gusts up to 50 mph at the highest ridgelines. Snowfall totals range from 2-15" of new snow. Lower elevation areas in Provo have received heavy rainfall, with close to 2.5" of water. Current snowfall totals are favoring upper-elevation terrain.

Today, an additional 1-3" of snow will fall with up to 0.2" of water by 5 PM. Temperatures will be in the upper-20s F. Winds will continue to decrease throughout the day, and into the evening. Mid-elevation winds will blow from the northwest averaging 5-15 mph with gusts below 25 mph and at the upper elevation ridgelines winds will average 10-20 mph gusting to 40 mph.

This is just the first in a series of three storms moving through Utah over the next week. After a break in the storms tomorrow, the following system should begin moving through the area on Friday.
Recent Avalanches
Some steep low elevation terrain gullies avalanched during the rain yesterday.
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Avalanche Problem #1
Persistent Weak Layer
Type
Location
Likelihood
Size
Description
Most avalanche activity on this persistent weak layer has been on northerly-facing terrain. This layer DOES exist at other aspects and elevations and it could begin producing avalanches when it gets loaded by heavy snowfall and strong winds.

The areas with the most uncertainty, and therefore highest level of concern for me are areas that have a generally substantial snowpack but have still been showing signs of propagation before this storm. These slopes will hold more water weight before they avalanche much wider and deeper. These will be unsurvivable avalanches. The uncertainty lies in the overall snowfall, water totals and how quickly we overload the snowpack. I am uncertain if this first system will overload the faceted grains enough to hit their tipping point, and for new snow and wind-drifted snow avalanches to begin stepping down deeper into this layer - but as we continue to add more snow and more wind, we do know that the likelihood of this happening will only continues to increase.
Today, I'd stay off of and out from under slopes over 30 degrees as the current snowpack adapts to the new snow and wind.
Avalanche Problem #2
Wind Drifted Snow
Type
Location
Likelihood
Size
Description
With high wind speeds and soft snow available for transport you are likely to find sensitive slabs of wind-drifted snow on all upper-elevation slopes, and mid-elevation terrain features that allow for drifting snow to accumulate. The new soft slabs will be most pronounced on lee-ward facing slopes, but with such high winds can load any aspect because winds swirl and change direction as they pass through the mountains, this is known as cross-loading.
What to do? Look for evidence of fresh drifts and wind slabs that look wavy, rounded, smooth, and pillow, and avoid steep terrain where you could trigger them.
Any wind slab avalanche that you trigger has the potential to step down into deeper weak layers in the snowpack.
Avalanche Problem #3
New Snow
Type
Location
Likelihood
Size
Description
Storm totals of 2-15" of new snow over the past 24 hours will create sensitive soft slabs of fresh snow on all aspects at mid and upper elevations. Expect the new snow to be sensitive during any period of higher precipitation intensity and watch for changing conditions.

Heads up: The lower elevations in the Provo area have received a lot of rain over the last 24 hours, up to 2.5" of water. While temperatures have dropped significantly and the saturated snowpack will hopefully freeze and not cause any issues, there is still some uncertainty with this much water. I would pay attention to low-elevation slopes that possess weak faceted early-season grains and show signs of remaining wet. If traveling through this lower elevation rain-soaked terrain I would avoid any location that haexperiencedrience an actual freeze, and one could sink through the entire snowpack to the ground. This could be a red flag that wet avalanches could still occur at these elevations.
Additional Information
Check out this weather discussion that Mark and I had talking about the forecast today, and areas of certainty versus uncertainty within the snowpack.
General Announcements
Help support the UAC while doing your Holiday Shopping. The UAC's Holiday Silent Auction opens at 8:00 AM MT on December 26 and will close at 8:00 PM MT on January 2. Take a look at items and bid HERE.

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.