UDOT PLANNED AVALANCHE CLOSURES!!

Forecast for the Salt Lake Area Mountains

Trent Meisenheimer
Issued by Trent Meisenheimer for
Sunday, February 5, 2023
Today there is MODERATE avalanche danger on all mid and upper-elevation slopes for triggering either a soft or hard slab of wind-drifted snow. Strong southerly winds have created slabs of wind-blown snow. Be on the lookout and avoid areas that have been or are being loaded by the wind.
As the new snow stacks up, the avalanche danger may rise from MODERATE to even CONSIDERABLE depending on the timing of the storm and how fast the snow falls from the sky.
Low
Moderate
Considerable
High
Extreme
Learn how to read the forecast here
Weather and Snow
The National Weather Service has issued a Winter Weather Advisory from Noon today to 5:00 pm Monday. This morning under mostly cloudy skies, the mountain temperatures range from 20-30 °F. Overnight southerly winds ramped up ahead of today's storm and are currently blowing 25-30 mph with gusts into the 40s at ridgetop. Winds will peak around 9:00 am this morning.
As today's storm approaches northern Utah, we expect the southerly winds to remain elevated through the morning hours. The surface front crosses the area around noon, while the upper-level level front crosses the area around 3:00 pm. Winds will gradually veer from south to west to northwest as the fronts move overhead. Snowfall should start around the lunch hour. Temperatures will climb into the low to mid-30s, and we could see 7-12 inches of new snow by sundown. By the end of the day on Monday, we could see 14-20 inches of new snow.
Recent Avalanches
No new avalanche activity was reported from the backcountry yesterday. See the full list of avalanche activity where you can filter avalanches by region and date.
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Avalanche Problem #1
Wind Drifted Snow
Type
Location
Likelihood
Size
Description
Southerly winds are blowing 25-30 mph this morning, and if I were getting into the upper-elevation terrain, my biggest concern would be shallow hard slabs of wind-blown snow. While many people traveled in the backcountry yesterday and reported the wind slabs to be unreactive, I would still be on guard today since the southerly wind is blowing once again.
As it starts to snow, look for slopes actively loaded by the wind and avoid those areas. With wind speeds, this strong, be on the lookout in the mid-elevation terrain as well. Terrain features like ridges, sub ridges or gullies, short steep break overs, or open bowls are all standard terrain features where wind slabs can form.
Avalanche Problem #2
New Snow
Type
Location
Likelihood
Size
Description
This avalanche problem will be determined by the storm's timing and how hard it will snow. As the storm snow stacks up, the avalanche danger will follow in lockstep. During periods of high precipitation intensity, we could see either dry loose avalanches or avalanche that fail within the new storm snow.
Remember Ed LaChapelle's "Ten Contributory Factors Leading To Direct Action Slab Avalanche Formation." Below are a couple of nuggets:
  • How will the new snow interact with the old snow surface?
  • 1" snow per hour for 12 hours with above critical wind = hazard
  • 10% density of new snow or greater = increased hazard
  • Need 10-12" new snow with wind to produce a significant hazard
  • Decreasing density = generally stable
  • Increasing density = generally unstable
  • rapid snowfall rates = rapid instability
  • Watch precipitation intensity trends during the storm
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.