Bollettino valanghe

Salt Lake

Pubblicato il Jan 5, 2023valido fino al Jan 6, 2023Utah Avalanche Center

Pericolo valanghe

Alta quota
Limite del bosco
Sotto il limite del bosco

Non aggiornato — questo bollettino è scaduto 4 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

The avalanche danger is CONSIDERABLE at upper elevation aspects facing west through north through southeast and mid-elevation aspects facing northwest, through north, through east where avalanches may step down into older facets, leading to large and destructive avalanches.

On the remaining upper and mid-elevation aspects, and low elevation aspects facing northwest, through the north, and through east where the persistent weak layer is less likely to cause avalanches the avalanche danger is MODERATE.

Today, natural avalanches are possible and human-triggered avalanches are likely.

While the avalanche danger is not as obvious as it was a few days ago, avalanche conditions remain dangerous. There is great riding to be had on slopes less steep than 30 degrees.

Problemi valanghivi

Persistent Slabs
N
NE
E
SE
S
SW
W
NW
Alta quota
Limite del bosco
Sotto il limite del bosco
Probabilità
Likely
Dimensione
4
This last storm was a significant loading event for our November faceted layer. Reports continue to come in of avalanches that ran on the persistent weak layer (PWL). With all the new snow insulating the old snow, I think we're well on our way to healing this PWL. That being said, I don't think it is completely healed yet. Yesterday, Eric and Drew reported a large audible collapse while approaching the crown to investigate the Meadow Avalanche. Red flags like that, in combination with the recent avalanche activity, is why the danger remains at CONSIDERABLE for today. We are in a situation where the likelihood is decreasing, but the consequence remains large. Any avalanche that fails into the November facets would be a bone-breaking, season-ending, deadly and destructive avalanche.

Nearly half of all avalanche accidents happen during times of considerable danger. Today is a day for careful snowpack evaluation and cautious route finding. Things are getting better, but we just need to give it more time - until then we can continue to enjoy low-angle powder skiing, and riding.

Updated avalanche heat map for the last 8 days (12/29/22-01/05/23) for Salt Lake area mountains. Excluding wet snow instabilities. As more avalanches continue to trickle in, we can see them primarily occurring on the W-N-E-SE facing aspects.
Wind Slabs
N
NE
E
SE
S
SW
W
NW
Alta quota
Limite del bosco
Sotto il limite del bosco
Probabilità
Likely
Dimensione
2
Winds picked up overnight and will remain strong along ridgelines throughout the day. With so much soft snow available for transport, you are likely to find sensitive slabs of wind-drifted snow on all upper-elevation slopes, and mid-elevation slopes that allow for drifting snow to accumulate. The new soft slabs will be most pronounced on lee-ward facing slopes, but elevated winds can load any aspect because winds swirl and change direction as they pass through the mountains, this is known as cross-loading.

Look for cracking, collapsing, and rounded pillows of new snow, and avoid steep terrain where you could trigger them. The main concern today is if any slabs of wind-drifted snow step down into the buried persistent weak layer.

Recent Activity

With great visibility yesterday, backcountry travelers continue to report avalanches that ran during the New Year's cycle, between 12/31 and 1/2. This includes both long-running sluffs and soft slab avalanches within the new snow, as well as much larger avalanches failing on the persistent weak layer.

The list of avalanches is growing rapidly, check out all of the recently reported avalanches HERE.

Yesterday, Drew and Eric went and investigated a large natural avalanche that occurred during the New Year's cycle. In Upper Silverfork, between Doug's Drop and the Football field, this large hard slab avalanche failed on the persistent weak layer up to 1000' wide, and 3-5' deep. Check out what they found below.

Yesterday, as the sun came out there were a few reports of wet-loose activity beginning on solar aspects.

Check out our observations page for the most recent information.

Snow and Weather

This morning, under overcast skies trailhead temperatures, are in the upper 20s F while ridgeline temperatures are in the mid-teens F. At mid-elevations winds are blowing 15-20 mph from the southwest with gusts up to 35 mph. At upper elevation ridgelines, winds are averaging 35 mph with gusts up to 75 mph.

Today, skies will be mostly cloudy with a chance of snow showers, increasing after 3 PM. Trace to 2" of new snowfall before 5 PM. Temperatures will climb into the upper-20s and low 30s F and winds will remain southwesterly averaging 10-20 mph at mid-elevations with gusts up to 30 mph and averaging 20-30 mph with gusts up to 55 mph at upper elevations. Along the highest peaks in the range, near 11,000' winds will remain elevated averaging 50-60 mph, with gusts up to 90 mph.

Tonight, the next system will cross the area bringing a good punch of moisture to the Cottonwoods and Provo Canyon. Snow will develop late this afternoon, and become quiet heavy into the evening hours with peak snowfall rates up to 2"/hr. Storm totals are expected to be 10-18" (0.8 - 1.6" of water).

Snow Depths throughout the Wasatch

Cottonwood Canyons 70-115"
PC Ridgeline 50-85"
Ogden Area Mountains 70-85"
Provo Area Mountains 50-90"

General Announcements

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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