Bollettino valanghe

Provo

Pubblicato il Dec 26, 2024valido fino al Dec 27, 2024Utah Avalanche Center

Pericolo valanghe

Alta quota
Limite del bosco
Sotto il limite del bosco

Non aggiornato — questo bollettino è scaduto 2 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

This morning, we have a MODERATE avalanche danger that will rise to CONSIDERABLE across upper elevation slopes facing northwest, north, northeast, and east, where it will become likely to trigger an avalanche 1-3 feet deep, failing on a persistent weak layer of faceted snow. There is also a MODERATE avalanche danger on mid-elevation slopes facing northwest through east for triggering an avalanche 1-3 feet deep that fails on a persistent weak layer of faceted snow.

With strong wind and heavy snowfall, the avalanche danger will rise over the next 24 to 48 hours.

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
2
Throughout northern Utah, we have a very weak and faceted snowpack on almost all shady slopes. If you look at the locator rose you will see the aspects and elevations highlighted in blue where the backcountry community and we have identified where this persistent weak layer of faceted snow exists (pwl).

Faceted snow is not dangerous until you add stronger, more cohesive snow (slab) over it. A slab over faceted snow (pwl) is the perfect recipe for avalanches that catch, carry, and kill most backcountry riders. In fact, it's responsible for roughly 70% of all avalanche fatalities.

Today, we have a rising avalanche danger as we build a slab of snow over this weak snow. Strong wind and heavy snowfall will overload the snowpack, creating dangerous avalanche conditions. I would avoid slopes steeper than 30 degrees in steepness and remember that an avalanche can be triggered remotely (from a distance).

Video: Discussion about the snowpack.

Recent Activity

No new avalanche activity was reported yesterday. On Tuesday, there were two avalanches. One was a very close call in Logan, where a rider was fully buried. The other was a skier-triggered slide in Upper Little Cottonwood.

Snow and Weather

Under partly cloudy skies, the first few snowflakes are falling, and mountain temperatures are cold ranging from 13-26 °F. In the past few hours, the wind has picked up out of the southwest, blowing 20-25 gusting into the 30s at Mid-Mountain Sundance. Within the past 48 hours, we've seen roughly 2-5 inches of snow with 0.10-0.45 inches of snow water equivalent (swe).

The National Weather Service has issued a winter storm warning for a series of winter storms that will impact northern Utah over the next few days. This morning, we should see snow begin to fill the area around 8:00 AM, with 2-4 inches of new snow (0.10-0.30 swe) throughout the day today. The wind is forecast to pick up in the next few hours and blow from the west at speeds of 15-25 mph with gusts into the 30s and 40s across the upper elevations.

This evening, a small cold front embedded in the flow will cross over northern Utah, bringing more snow overnight into Friday. All said and done, we could see 12 to 28 inches of new snow (1.40-2.90 swe) by Monday (see total precipitation map below).

Additional Info

An avalanche watch means we will likely transition into an avalanche warning within 24 hours.

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