Boletín de aludes

Salt Lake

Publicado el Dec 30, 2025válido hasta el Dec 31, 2025Utah Avalanche Center

Peligro de aludes

Alta montaña
Límite del bosque
Bajo el límite del bosque

Desactualizado: este boletín caducó 8 months ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

You'll find a MODERATE avalanche danger in the backcountry. While you'll likely encounter wet loose, dry loose, and soft slabs of wind blown snow in their respective locations, it's the hard slab that you trigger with no warning that steps 2-3' deep down into a PWL of faceted snow that'll kill you. The first three issues are high probability - low consequence (except in unforgiving terrain), the last issue is low probability - high consequence. Read on for more info.

HOT TIP! - The best and safest skiing and riding is on low angle shady slopes of the mid and upper elevations.

Problemas de aludes

Storm Slabs
N
NE
E
SE
S
SW
W
NW
Alta montaña
Límite del bosque
Bajo el límite del bosque
Probabilidad
Likely
Tamaño
2
Sluffing of the storm snow will again be prevalent today, particularly on the steepest solar aspects as the storm snow transitions to damp and then wet with today's sun and rapidly rising temperatures. WET SLUFFS will run naturally and with provocation and will run fast/far and entrain lots of snow as they cascade down the slick Christmas Eve rain crust (CERC!). Pinwheels, rollerballs, and natural sluffs are clear signs you've started to overstay your welcome and it's time to change aspects. Note natural wet sluff over the Hellgate Cliffs in upper LCC yesterday.

DRY SLUFFS (aka Dry Point Releases) are also possible in the low density storm snow in very steep terrain. Again, the rain crust is the compounding issue as the loose snow wants to run fast and far on the slick crusts.

Because of the sneaky overnight winds, don't be surprised to find newly formed SOFT SLABS OF WIND DRIFTED SNOW along the highest elevation bands. These will be most prevalent on north to east to south facing slopes and may be triggered at a distance.

Example photo from Sean Hathcock. His excellent report from the Brighton backbowls can be found HERE>
Persistent Slabs
N
NE
E
SE
S
SW
W
NW
Alta montaña
Límite del bosque
Bajo el límite del bosque
Probabilidad
Possible
Tamaño
2
There is a persistent weak layer (PWL) of weak, faceted snow and depth hoar down near the ground on northerly-facing aspects above about 9,000 feet. Sunday's avalanche on Sunset Peak failed on this PWL, control work from resorts also indicate avalanches failing on the PWL remain possible, and full propagation with extended column tests on this PWL continue.

Dealing with a PWL is already tricky business, and now the Christmas Rain Crust further complicates things as the crust may be strong enough on some slopes to support the recent load of new and wind-drifted snow, while other slopes may have a thinner crust where a rider may be able to affect the PWL and trigger an avalanche up to three feet deep and over a hundred feet wide. Ski cuts are notoriously ineffective tools at mitigating this problem as they often allow you to get well onto a slope before triggering an avalanche that propagates above you; existing tracks on a slope are also not an indication of stability (there are plenty of tracks adjacent to the Sunset Peak slide.)

Nikki Champion was near Davenport Hill in Silver Fork on Sunday and her video describes the current snowpack structure where the Christmas Rain Crust further complicates our PWL problem.

Recent Activity

A skier descending Two Trees (south facing terrain east of Superior) triggered and was caught and carried in a loose sluff as he entered very steep and rocky terrain through the choke. His report can be found HERE. This makes four backcountry skiers caught and carried (in either shallow slabs of wind blown snow or loose dry or wet sluffs) in the past two days with one very close call on Sunset Peak on Sunday. More below. In upper Little Cottonwood, avalanche control teams were able to trigger some new snow avalanches running on, or just above, the rain crust.

Sunset Peak - North aspect at 10,300 feet that ran on the persistent weak layer (PWL). This was 2.5 feet deep and 80 feet wide, with debris running to the apron below. Fortunately, the rider was not caught. Photo below.

Human-triggered avalanche on Sunset Peak failing on the Persistent Weak Layer.

Snow and Weather

Skies are clear, ain't it a shame..

Winds are from the west-northwest, blowing 10-15mph EXCEPT! along the highest peaks and ridgelines where they sneakily increased to 25-30mph with gusts to 35mph overnight.

Mountain temperatures are inverted under the ridge of high pressure with temps in the mid to upper 20s up high, the low teens down low. Note that these upper level mountain temperatures are 10-15°F warmer than this time 24 hours ago.

Longtime backcountry skier/alpinist John Climaco finding the goods along the PC ridgeline

Look for mostly sunny skies today, with mountain temps rising to the mid to upper 30s. I expect the winds to lose steam and be generally light today from the west-northwest. We'll see even warmer temperatures tomorrow ahead of warm and potentially wet storm arriving from the southwest Wednesday night. Storm totals may be 4-8" but with a rough rain-snow line at 8000'. Potentially unsettled (active?) late weekend into next week.

Skiing and riding conditions are excellent: fast (occasionally too fast; see below) and supportable with the post Christmas storm powder on top of the Christmas Eve rain crust. The best (and safest) turns are found on the low angle mid and upper elevation shady aspects; otherwise you're scraping your tails on the rain crust or just getting sluffed with the loose snow. Snow coverage is 30-40 inches on the polar aspects up high and a measily 0-6" down low.

Additional Info

Good supplementary reading by Alaska IFMGA guide and book author Joe Stock - Luck and Avoiding Avalanches

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.

Observations and Avalanches

Backcountry Emergency Procedures