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Forecast for the Logan Area Mountains

Mark Staples
Issued by Mark Staples on
Friday morning, December 24, 2021
Today both natural and human-triggered avalanches are very likely at upper elevations facing East, West, and North where the avalanche danger is HIGH. All other slopes at mid and upper elevations have a CONSIDERABLE danger. At low elevations, avalanches will be possible and the danger is MODERATE.

Heads up - Today's snowfall is a major test of the snowpack which is guilty until proven innocent. Give yourself a wide safety margin today and avoid avalanche terrain.
Low
Moderate
Considerable
High
Extreme
Learn how to read the forecast here
Avalanche Warning
AN AVALANCHE WARNING HAS BEEN ISSUED FOR THE MOUNTAINS OF MUCH OF THE STATE OF UTAH, INCLUDING THE WASATCH RANGE...BEAR RIVER RANGE...UINTA MOUNTAINS...THE MANTI-SKYLINE...THE FISH LAKE REGION…PAHVANTS…TUSHARS…AND THE CEDAR CITY AREA MOUNTAINS.
HEAVY DENSE SNOWFALL AND STRONG WINDS WILL LIKELY CREATE VERY DANGEROUS AVALANCHE CONDITIONS. BOTH HUMAN TRIGGERED AND NATURAL AVALANCHES ARE LIKELY. STAY OFF OF AND OUT FROM UNDER SLOPES STEEPER THAN 30 DEGREES.
Special Announcements
Avalanche conditions are very dangerous across most of the State of Utah as discussed by our staff in the video below -
Weather and Snow
As of 4 a.m. 8-12 inches of VERY dense, heavy snow has fallen since yesterday containing 1.0-1.7 inches of water, and it's still snowing. Temperatures are mostly in the upper 20s F while they are above freezing in the Cache Valley. Winds yesterday from the south-southwest blew 35-40 mph with gusts of 60 mph. They have eased this morning blowing 26 mph gusting 48 mph from the west-southwest.
Today, temperatures should hold steady or even drop a degree or two. Winds from the west-southwest could pick up some this afternoon. Snowfall should continue through the day with about another 10-12 inches accumulating by tomorrow. Snowfall may slow down a little tomorrow afternoon, but then it should ramp up again Sunday morning.
Recent Avalanches
There were no avalanches reported yesterday, but that doesn't mean there weren't any. I suspect there were some natural avalanches overnight during the heaviest snowfall periods.

Check HERE for all the latest observations and avalanche activity.
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Avalanche Problem #1
Persistent Weak Layer
Type
Location
Likelihood
Size
Description
Slab avalanches breaking on a persistent weak layer near the ground are likely today. This layer of weak, sugary facets can be found just above a hard ice crust that caps old snow from October and early November. The tricky part about this layer in the Logan area mountains is that it is not as widespread or as obvious as it is in other parts of the state. In some ways, this scares me more. This layer is on some slopes but not others. We're still collecting data on where this layer exists, but for now, the only safe option is to assume it exists on any slope that had old snow on it at the start of November.
Avalanche Problem #2
Wind Drifted Snow
Type
Location
Likelihood
Size
Description
Winds from the south blew 35-60 mph yesterday afternoon. These winds drifted snow mostly on slopes that have a persistent weak layer of sugary facets near the ground. The problem with these wind slabs is that they will make avalanches breaking on the facets larger, deeper, and more deadly. Avoid any steep slope, and especially avoid any slope with obvious wind drifting where avalanches are very likely to occur.
Avalanche Problem #3
New Snow
Type
Location
Likelihood
Size
Description
On slopes that don't have wind drifted snow and don't have old facets near the ground, the new snow alone may produce soft slab avalanches. Subtle variations in the new snow like density changes can create a temporary weak layer. Fortunately these instabilities can be short lived, but they remain a concern as long as it is snowing.
Additional Information
  • Always follow safe backcountry travel protocols. Go one person at a time in avalanche terrain, while the rest of your party watches from a safe area.
  • Check your avalanche rescue equipment, change your batteries, and practice often with your backcountry partners.
  • Be very careful, keep your speed down, and stay in control. Encounters with shallowly buried rocks or down trees in the early season have led to many season-ending injuries.
  • The gate at the bottom of the Tony Grove Road was closed yesterday to preserve snow on the road for grooming.
General Announcements
Who's up for some free avalanche training? Get a refresher, become better prepared for an upcoming avalanche class, or just boost your skills. Go to https://learn.kbyg.org/ and scroll down to Step 2 for a series of interactive online avalanche courses produced by the UAC.
  • Check out all the upcoming education classes and clinics HERE.
  • Please submit your observations from the backcountry HERE.