Bollettino valanghe

Ogden

Pubblicato il Jan 12, 2023valido fino al Jan 13, 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 all upper elevations and at mid-elevation aspects facing west through north through southeast where heavy snowfall and strong winds have created dangerous avalanche conditions. New snow and wind-drifted snow avalanches may step down into older facets, leading to large and destructive avalanches.

At all lower elevations and mid-elevation aspects facing southwest, and south where the persistent weak layer is less likely to cause avalanches the avalanche danger is MODERATE.

Careful snowpack evaluation, cautious route-finding, and conservative decision-making will be essential today.

Problemi valanghivi

Wind Slabs
N
NE
E
SE
S
SW
W
NW
Alta quota
Limite del bosco
Sotto il limite del bosco
Probabilità
Likely
Dimensione
3
While the winds have backed off this morning, days of high winds in combination with soft snow available for transport will have formed sensitive slabs of wind-drifted snow on all mid and upper-elevation slopes. These 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.

Any wind-drifted avalanche may step down into a deeper buried weak layer resulting in a larger avalanche.

Example of the soft slab avalanches of wind drifted snow you could find today. Brighton Hill - B. Nalli. Find full observation HERE.
Storm Slabs
N
NE
E
SE
S
SW
W
NW
Alta quota
Limite del bosco
Sotto il limite del bosco
Probabilità
Possible
Dimensione
3
Out of the wind zone you may still be able to find a sensitive soft slabs of new snow and fast, long-running sluffs on all aspects at mid and upper elevations. While new snow avalanches can be consequential on their own - the primary concern is if they step down into the buried persistent weak layer.
Persistent Slabs
N
NE
E
SE
S
SW
W
NW
Alta quota
Limite del bosco
Sotto il limite del bosco
Probabilità
Unlikely
Dimensione
4
The deeply-buried persistent weak layer (PWL) from November continues to gain strength and it has become harder to initiate an avalanche on this layer. It may take a significant trigger - this could include a large cornice fall, multiple riders on a slope at a time, or another avalanche adding more weight to the snowpack, and stepping down to trigger this layer. Any avalanche triggered on this weak faceted snow would be 2-7' deep.

We have begun seeing avalanches that could be stepping down into this PWL. This is a heads-up that we could be hitting the tipping point in additional snow load and overall additional weight and may continue to see more avalanches stepping down into the weak facets.

Areas where you are more likely to trigger this PWL, are shallow thinner spots, rocky ridges, and mid-elevation terrain.

This report from Parley's Canyon still shows weak faceted snow buried under 3' of harder-density snow.

Recent Activity

In the backcountry, multiple user observers triggered sensitive soft slabs within the new snow and wind-drifted snow. As visibility improved, there were also reports of larger natural avalanches that failed deeper in the snowpack. One impressive avalanche reported was on the NW side of Thurston Peak, near the top of Kay's Creek. This avalanche failed on a Northwest aspect near 7400'.

Ski resorts reported sensitive soft slabs of wind-drifted snow and new snow running fast and far with both ski and explosives.

Thurston Peak Avalanche - Find full observation HERE.

Find all recent avalanches HERE.

Snow and Weather

Overnight mountain locations reported a trace amount of new snow, and 1-3" of new snow since yesterday morning. That brings final storm totals up to 20-36" of snow.

Under mostly clear skies, temperatures are in the mid-teens to low 20s F. Winds have transitioned more west, south westerly, and are blowing 10-20 mph, with the upper elevation ridgelines gusting up to 30 mph.

Today, skies will be partly cloudy temperatures will climb into the mid-30s F. Winds will continue to decrease, blowing 5-15 mph at mid-elevation ridgelines, and blowing 15-25 mph with gusts up to 30 mph at the highest ridgelines. Some light snowfall is possible Saturday with a weakening through, but otherwise, the next real storm should arrive Sunday.

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