Bollettino valanghe

Provo

Pubblicato il Jan 2, 2025valido fino al Jan 3, 2025Utah 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

The avalanche danger is CONSIDERABLE. You can trigger both new and old snow avalanches in steep terrain, particularly terrain that has been recently wind drifted. Natural avalanches are possible. The most dangerous areas will be on or beneath northwest to east facing slopes at the mid and upper elevations. Remember that you'll be able to trigger avalanches at a distance.

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
3
The overnight snow and wind may be enough stress to make triggering deep and dangerous avalanches likely again today. Natural activity is possible in some areas. We clearly have a strong slab 2-4 feet thick overlying a persistent weak layer (PWL) of weak sugary faceted grains and there's no mystery here: avalanches, cracking and collapsing are nearly omnipresent.

Remember that as these overlying slabs gain strength, they can propagate wider and pull back onto lower angle connected slopes.
Wind Slabs
N
NE
E
SE
S
SW
W
NW
Alta quota
Limite del bosco
Sotto il limite del bosco
Probabilità
Possible
Dimensione
2
You will be able to trigger freshly wind drifted slopes today. These cakey soft slabs up to 18" thick will be most pronounced on mid and upper elevation slopes with an easterly component, but avoid any slope with recent deposits of wind drifted snow.
Storm Slabs
N
NE
E
SE
S
SW
W
NW
Alta quota
Limite del bosco
Sotto il limite del bosco
Probabilità
Possible
Dimensione
2
New snow soft slab avalanches should also be easy to trigger today in the upside down snow. To cast a wide net, there are actually a number of failure planes that could be active today that might include weakness associated with last week's rain/rime crusts or thin crusts on the solar aspects. The snowpack is becoming more complex, not less so.

Special Announcement

We are deeply saddened to confirm two avalanche fatalities. The first involved a 38 year old man in Main Porter Fork of Mill Creek Canyon who went missing on Saturday. The second avalanche fatality occurred Tuesday that involved a 54 year old man off Davenport Hill into Silver Fork of BCC. Both individuals were traveling alone in the backcountry. Our condolences go out to to the family and friends of the victims.

Many thanks to those who responded to these accidents: search and rescue teams from AirMed, LifeFlight, Utah Dept Public Safety, Utah Department of Transportation, Salt Lake County Search and Rescue, Wasatch Backcountry Rescue, Alta Ski Area, and members of the Utah Avalanche Center.

Main Porter Preliminary Accident Report (1st photo - SL County SAR) Original avalanche obscured by recent snow/wind. Avalanches in photo are from explosives to protect rescuers.

Davenport Hill Preliminary Accident Report (2nd photo - Wasatch Backcountry Rescue) The victim was buried 20 feet deep.

Recent Activity

We did not hear of any avalanches in the Provo mountains yesterday, but there were many sighted or triggered on Tuesday, especially as you work back around toward the Ant Knolls area of Snake Creek.

From Tuesday in the Salt Lake and Provo area mountains: there were another ten avalanches triggered in the backcountry, including the fatality on north facing Davenport Hill into Silver Fork.

The list includes Butler Basin, Meadow Chutes, Lavina Creek, Ant Knolls, Little Water, Summit Park, Sheep Shit Ridge, Lackawaxen, Murdock Peak, and Davenport. These were 2-4 feet deep and 200 feet wide on generally north through east facing aspects at 9500' or so. Nearly all were triggered from a distance. This pushes our totals to just over 50 reported avalanches since Friday now failing on our old weak persistent weak layer (PWL) of faceted snow from early season.

For all recent observations, click HERE

Snow and Weather

We call these "Warm fronts"..."Warm air advection"...With a little bit of lift in the atmosphere, we get heavy dense snow becoming denser with the storm, rising temperatures, wind and maybe some rime to cap things off. It's a storm only a mother could love. As of 6am, the Provo mountains have just picked up 2-4" of heavy dense snow with rain at the lower elevations.

Mountain temperatures are rising and are in the upper 20s to low 30s. Winds are blowing from the west northwest, blowing 15-20mph with gusts to 30. Along the highest ridgelines, winds are averaging 35-40mph with gusts to 65. Yuk.

Snowfall and wind should start to taper off by late morning and we may squeeze another trace to 2" before it's all said and done. Winds will blow 15-20mph from the west-northwest. Mountain temperatures will be in the upper 20s rising to the mid to upper 30s overnight(!) A brief and transitory shortwave ridge builds in tonight into tomorrow to bring clearing overnight into Friday. Temperatures remain warm tomorrow ahead of Saturday's cold front. "Storms" are on tap Saturday, Sunday, and possibly early week. None of them look like blockbusters, but they'll add up to something.

Skiing and riding conditions today will be variable: areas of surfy graupel, areas with wavy wind drifts, areas of cakey upside down snow.

Additional Info

Researchers Ian McCammon and Kelly McNeil looked into safety habits that markedly increase our margins of safety. Please take a moment to look over these and recalibrate your safety habits: Six Tips That Could Save Your Life (Recent updates to Safety Messaging)

General Announcements

CLICK HERE FOR MORE GENERAL INFO AND FAQ

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