Bollettino valanghe

Ogden

Pubblicato il Mar 29, 2023valido fino al Mar 30, 2023Utah Avalanche Center

Pericolo valanghe

Alta quota
Limite del bosco
Sotto il limite del bosco

Non aggiornato — questo bollettino è scaduto 3 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

The avalanche danger is CONSIDERABLE on steep upper elevation slopes facing northwest to east to southeast where strong winds and recent storm snow have created unstable slabs of wind-drifted snow. A MODERATE danger exists for triggering both loose dry and soft slab avalanches on the remaining upper elevation aspects and all mid-elevation slopes.

Both wind-drifted and new snow avalanches will likely fail 1-2’ deep, but have the potential to fail deeper at the new/old snow interface that is now down 2-5’ in places. For that reason, cautious route-finding, and conservative decision-making will be essential today.

With the high winds and warm temperatures, natural cornice fall will be likely today. Give cornices, and slopes below cornices a wide berth.

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
2
The bump in southwest winds, plus soft snow available for transport will have formed soft slabs of wind-drifted snow at all mid and upper elevations. With the winds slated to remain elevated, these shallow slabs will only continue to grow, and become more cohesive throughout the day. This could allow for a rider to be farther out on a slope before it breaks, or to trigger these avalanches remotely, from a distance.

These avalanches will be most pronounced on upper elevation northwest to east to southeast facing terrain, but such high 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 slopes with any signs of wind-drifted snow, such as cracking, hollow noises, and pillow-shaped snow, and avoid those slopes.

Photo of wind-drifting snow at the highest ridgetops above American Fork. D. Kelly

Cornices: Yesterday we got a few reports of natural cornice fall. Cornices are currently large and only continue to grow in the backcountry. With today's warm temperatures and high winds, we will continue to see more cornices breaking naturally. Give cornices, and the edges of cornices a wide berth as they often break farther back than expected. Limit your exposure to slopes below cornices. A cornice fall could trigger a larger slab of wind-drifted snow below.
Storm Slabs
N
NE
E
SE
S
SW
W
NW
Alta quota
Limite del bosco
Sotto il limite del bosco
Probabilità
Possible
Dimensione
2
Out of the wind zone, both slab and loose snow avalanches may break within the different layering of new snow from the past week.

These avalanches may fail within the new snow (1-2' deep) or at the new snow/old snow interface (which is now 2-5' down) as we saw near the Ant Knolls, Rainbow Peak, and Mill B. It has also been reported that some new snow avalanches have then stepped down to this older interface from last week. These could be large and deadly avalanches, as Drew said yesterday "the snowpack is more rich, complex, and interesting than I want it to be right now." We have just received so much snow with very little break, the snowpack has not had time to adjust to these large stressors.

Until the snowpack stabilizes, or we get more time between storms, I plan on sticking to lower-angle slopes. If you dochoosee to step out into steeper terrain, choose terrain that won't kill you if you get caught off guard.

Wild card: It's almost April, and that sun is strong. The high wind, and increased cloud cover should keep the wet snow at bay today - but any periods of strong sunshine could spike the avalanche danger, and wet snow avalanches could run. If the snow becomes damp and you start seeing rollerballs and sluffing, it will become time to switch aspects and choose low-angle terrain.

Special Announcement

On Monday, March 27, two snowmobilers were riding in the Oquirrh Mountains. One was caught, carried, and fully buried in a very large avalanche. His partner, friends and family, Utah County Search and Rescue, Utah Department of Public Safety, and LifeFlight participated in the rescue, but he sadly did not survive. The preliminary avalanche report can be found HERE.

Our sincerest condolences go out to everyone affected by this tragic avalanche.

We are in the process of finalizing a report about the March 9th avalanche fatality in the Uintas. Thank you for your patience, and we will publish the final report in coming days.

Thank you to everyone who donated to our Spring Campaign. We appreciate your support and look forward to creating new tools to help you stay safe in the backcountry.

Recent Activity

Yesterday, was a busy day in the backcountry. Around noon on Tuesday, March 28th, we received a report of a snowcat-triggered avalanche in the Morgan area which took the cat for a ride through a group of trees, overturning it in the process and injuring a passenger. Details and location are still being sifted through, more information will become available as we receive it.

Photo: KSL 5

Over 10 avalanches were reported from the Central Wasatch backcountry. Primarily soft slabs of both new snow, and wind-drifted snow at the mid and upper elevations. With the good visibility, a few impressive naturals were reported that likely occurred between the 26th and 27th, including a large avalanche from Mill B and Rainbow Peak.

Find all recent observations HERE.

Snow and Weather

This morning, skies are broken and mountain temperatures are sitting in the upper 20s and low 30s F. Winds remained elevated since yesterday, blowing from the southwest at speeds of 15-25 mph, with gusts up to 55 mph.

Today, a strong southerly flow will continue through the evening ahead of the approaching low-pressure system. Skies will be mostly cloudy, and temperatures will climb into the mid 30s F. Winds will remain south, southwesterly averaging 25-35 mph, with gusts up to 45 mph. At the highest ridgelines winds will gust up to 60 mph. Snowfall will begin mid to late afternoon before becoming more consistent this evening. The mountains could get a trace amount of new snow before 5 PM.

Outlook, yet another powerful Pacific storm is on deck. We'll see increasing clouds and southwest winds today ahead of at-times heavy snowfall tonight through Friday. Snowfall will peak this evening, with the heaviest snowfall arriving overnight. The mountains could get 5 -8" of new snow before sunrise.

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