Bollettino valanghe

Salt Lake

Pubblicato il Feb 15, 2024valido fino al Feb 16, 2024Utah 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

Today, the avalanche danger is CONSIDERABLE on all mid and upper-elevation steep slopes for triggering soft slabs of Wind-Drifted Snow. We also have a CONSIDERABLE danger for New Snow dry-loose (sluffs), or soft slab avalanches failing within the recent storm snow. Strong winds and heavy snowfall will increase the avalanche danger throughout the day. Cautious route-finding and conservative decision-making will be essential today. On slopes facing west through north through east across the mid and upper elevations, it remains possible to trigger a hard slab avalanche breaking 4-6' deep on buried faceted snow.

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
We have now seen close to 24 hours of elevated wind speeds from the southwest. This morning, the southwest wind continues to blow at speeds of 15-25 mph with gusts in the 30s and 40s. These are the perfect speeds to drift snow onto lee slopes. With wet heavy snowfall throughout the day and plenty of soft, dry snow to blow around I would expect to find soft slabs of wind-drifted snow across all mid and upper-elevation steep terrain. These slabs could be 1-3 feet deep and up to 200 feet wide.

Heads up: We have been finding buried surface hoar and small-grained faceted snow in sheltered locations (see Hardesty/Meisenheimer observation). Plus we have this weekends very low-density snow (2-3%) that is now buried and preserved (stellar crystals). If any of those grains come into play, the soft slab or wind slab will be much more electric.
Storm Slabs
N
NE
E
SE
S
SW
W
NW
Alta quota
Limite del bosco
Sotto il limite del bosco
Probabilità
Likely
Dimensione
2
This avalanche problem will depend on the storm and how the new snow falls from the ski. If we see snowfall rates of 1" per hour or more this morning I would expect to see widespread dry-loose avalanches as well as soft slabs failing within the new storm snow or at the old/new snow interface. I would be cautious as the new snow stacks up. Use shovel tilt tests or small tests slopes to see how the new snow is bonding before committing to steep terrain.
Persistent Slabs
N
NE
E
SE
S
SW
W
NW
Alta quota
Limite del bosco
Sotto il limite del bosco
Probabilità
Possible
Dimensione
3
This avalanche problem remains a concern, particularly in the most suspect areas: steep, shallow, and rocky terrain features or shallow areas that have previously avalanched this season. If you trigger this layer, it's likely to break 4-6 feet deep into dry faceted snow. As we saw over the weekend, these avalanches may be hundreds of feet wide, run thousands of vertical feet downhill, and are likely unsurvivable.

This past weekend, we had several close calls and very large avalanches. Read and click through the following: Lisa Falls / Pioneer Ridge / Main Gobblers / Cardiac Ridge / Pole Canyon. You can find a list of all avalanche activity HERE.

Recent Activity

Yesterday, snow safety teams reported shallow soft slabs that were easy to trigger with skis. One backcountry guiding group reported triggering a few shallow soft slabs. Mark Staples was in Bountiful and was able to trigger a shallow, but wide wind slab off an upper elevation ridge. The avalanche was roughly 200 feet wide failing on buried stellar snow (photo below).

Snow and Weather

The National Weather Service has issued a Winter Storm Advisory for the mountains south of I-80. In the past 24 hours, we picked up another 1-3 inches of new snow, bringing the snow totals since Wednesday to roughly 4-8 inches of snow with (0.10-0.40 water).

This morning, the next storm is on the doorstep and the first few snowflakes are hitting the boards. Overnight, the southerly winds picked up and continue to blow 15-25 mph with gusts into the 30s & 40s across the upper elevations. Mountain temperatures range from 20-25 °F.

Today, we should see 5-10 inches of new snow throughout the day, with the peak intensities happening mid-morning. The wind will continue to blow from the southwest at 15-25 mph with gusts into the 30s and 40s for much of the day. At some point, the wind will veer to the west and eventually blow from the northwest later today. The storm will be short-lived but should stack up 10-15 inches of new snow by Friday afternoon.

This weekend a large closed low sets up off the California Coast and looks to park there for a few days. This closed low will usher in a moist southwest flow and, depending on where the waves of moisture hit, will determine how much snow we get. But this storm looks to be warm and wet.

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.

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