Bollettino valanghe

Provo

Utah Avalanche Center
Vedi sulla mappa

Pericolo valanghe

  • Alta quota
  • Limite del bosco
  • Sotto il limite del bosco
Open full map
Non aggiornato — questo bollettino è scaduto 7 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

The avalanche danger is CONSIDERABLE on all aspects on mid and upper elevation slopes. Triggering a wind drift or new snow slide is likely, and natural avalanches are possible, running long distances in the continuously steep terrain in the Provo area mountains. Even in wind sheltered terrain, new snow slides a foot deep can be triggered or wet loose sluffs at the mid elevations. Careful snowpack evaluation, cautious route finding and conservative decision making are essential for backcountry travel today. Avoid avalanche run out zones. There is a MODERATE danger on low elevation slopes for triggering a wet, loose sluff, especially during any periods of rain or of clearing skies and sun.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    3

    Strong overnight winds from the southeast to southwest (averaging 30 to 35 mph, with gusts in the 40s and 50s) drifted the new snow into dense slabs. These drifts will be most widespread on northwest through easterly facing slopes at the upper elevations. The drifts could be 2 feet deep, and will be very reactive to a person or ski cuts on steep slopes, resulting in avalanches large enough to carry and bury a person. The strong overnight winds will have also deposited snow well off the ridge lines and cross loaded drifts onto other aspects, slope break overs and along sub ridges and at the mid elevations, too. Cracking in the snow is a sign of a wind drift.

    Even out of the wind affected terrain, weak layers within the new snow and poor bonding to the old snow surfaces means you can trigger new snow slides up to a foot deep. On the shady slopes, the new dense snow fell on weaker low density snow and on the sunny slopes it landed on a hard crust. The new snow will be most sensitive during any periods of intense snowfall. Jumping on small test slopes can help give you a feel for the bonding of the new snow.

    The large cornices will be more sensitive today with the added weight of the new snow on top. Stay way back from the edges, and don’t travel beneath them.

    Photo by Mike and Fabian of cornice triggered wind slab, and note the large cornices along the ridge line.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    3

    The Provo mountains have had a number of large avalanche cycles in January and February with many avalanches stepping down into early season or mid-December snow layering 3-8' deep. These avalanches were predominantly in the upper elevation (or wind loaded ridgelines in the mid-elevation) north through southeast facing slopes both along the Cascade ridgeline, Timpanogos, and in the upper American Fork drainages (Mill Canyon Peak environs).

    These areas that avalanched remain susceptible to continued avalanching in the upper elevations that have seen significant snow and wind. The large avalanches in the UFO Bowls north of Aspen Grove (from the 3rd week of February) did not seem to have enough of a new load yesterday but will be something to watch with additional storms this week.

    Note: assessing these slopes individually requires a high degree of skill and experience and risk....and may still produce some uncertainty. A very conservative approach is required if traveling in the avalanche terrain of Provo.

    Mt Nebo area: Although outside of our forecast zones, Trent and I rode along the Mt Nebo Scenic Loop yesterday and found similar conditions to areas further north. Read our full observation HERE.

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    2

    Though temperatures have cooled slightly, it will take time for the soggy snow at the low elevations to cool and strengthen. It will still be easy to get a wet loose sluff moving on steep slopes, and wet loose naturals are still possible especially during any periods of rain. Avoid steep slopes with wet soggy snow, especially gullies, creek banks or road banks where even a small slide can pile up deep debris.

Recent Activity

Yesterday, sensitive new snow soft slabs were easily triggered with ski cuts, averaging 6 to 10” deep in the wind drifted zones of the Cottonwoods. Wet loose sluffs ran at the low to mid elevations in the Provo area mountains.

Provo: natural wet loose sluffs in the Fingers on Timpanogos, 7,400’, NE, Shannon Finch photo

Numerous roofs avalanched yesterday, dumping large loads of snow into deep dangerous piles. (Matt Rollins video) Warm temperatures mean roofs will continue to shed their snow - please alert your friends and family who may not normally check avalanche forecasts. Roof avalanches can be deadly especially for children.

Snow and Weather

Someone gave the snow globe a shake last night, and another 4 to 7” of dense snow fell in the Provo area mountains, with the rain/snow line now above 7,000'. The storm snow is dense, averaging over 12%, at mid elevations, low elevation have a couple of inches of snow sitting on the rain soaked old snow. There is now about 2" of water weight from the combination of snow and rain. Temperatures have finally cooled to right around freezing at the mid and lower elevations.

Today: continued snow, tapering off this afternoon. An additional 2 to 4” of snow is possible. Winds will remain from the southwest, and should decrease, averaging 10 to 20 mph, with gusts in the 30s. Speeds along the exposed higher ridge lines favored by southwest flow could still average 30 mph, with gusts in the 40s at times. Temperatures will warm into the mid 30s at 8,000', and hopefully the rain/snow line will remain below 6,500’ today.

A brief break is expected this afternoon and evening before another colder system brings more snow overnight into early Friday.

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.

Regioni coperte