Avalanche Advisory
Advisory: Provo Area Mountains Issued by Evelyn Lees for Saturday - February 11, 2017 - 7:26am
bottom line

The avalanche danger is HIGH this morning on steep low elevation slopes of all aspects where both natural and human triggered wet snow avalanches are likely. The avalanche danger is CONSIDERABLE at the mid and upper elevations. Back country travel in the Provo area mountains is not recommended.




special announcement

There are road closures this morning in Provo Canyon and SR92. Check utahcommuterlink.com for up to date information.

current conditions

Storm totals of snow and rain:

  • Provo area mountains: 8” of snow, on top of rain soaked snow, at the mid elevations. At the lower elevations, up to 3.5 inches of water, all rain at the lower elevations.

After two days of strong southwesterly winds, speeds started to decrease yesterday afternoon as the snow came in, and really dropped as the front passed. Winds are now from the northwest and very light, less than 15 mph at most stations.

recent activity

A large mud/snow avalanche has covered the Provo canyon road this morning. No details until it gets light. Control work is triggering slides in Little Cottonwood this morning. Thursday night, a large natural cornice broke loose above 11,000’ in Little Cottonwood, triggering a 2-3’ deep, 100’ wide, far running slab avalanche.

Avalanche Problem 1
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 24 hours
description

Storm snow - Up high, the combination of “right side up” new snow (dense snow with increasingly lighter snow on top), light winds and warm temperatures is a good thing. The new storm snow will be most sensitive early this morning, with human triggered slides likely on steep slopes

Wind drifts - the winds have blown from southwest through northwest in the past 18 hours, so new drifts could be on a variety of aspects, mostly along the upper elevation ridge lines.

Cornices are still an issue. Both old and new cornices are sensitive, break back further than you would expect, and breaking off one of the large cornices could trigger a new snow slide on the slope below.

Avalanche Problem 2
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 24 hours
description

After days of warm temperatures and rain on snow to over 8000’, a few hours of cooling isn’t going to be a quick fix. Rain and warm temperatures have soaked and weakened the old snow. Both natural and human triggered wet snow avalanches are likely at the lower elevations.

Even at the mid elevations, wet snow is now hidden beneath the new snow. The new “dry” snow will act just like wet snow once you get it moving. Below around 8000’, any sluff you trigger will turn into a wet sluff – with dense, cement like debris, and even small steep terrain features such as road and creek banks can pile up enough debris to bury a person.

Be very alert for changing conditions as you change elevations today. Cold dry snow up high on a slope can transition to wet loose snow over a short drop in elevation, surprising you. Daytime heating with thinning clouds or any glimpses of sun could also heat the new snow and rapidly increase its sensitivity.

weather

As the storm moves south out of the area, the mountains should receive light snow through about noon, adding up to 2 to 4” in areas favored by northwest flow. By around noon, skies should be partly cloudy, and temperatures warm – highs in the low 30s at 8000’, and low 20s at 10,000’. The northwesterly winds should remain light all day, averaging less than 15 mph. Even the highest peaks will only gust into the 30s.

High pressure will build back in on Sunday and remain through Thursday, with unseasonably warm temperatures once again by early next week. The next storm Friday looks to be another warm one.

general announcements

Remember your information can save lives. If you see anything we should know about, please help us out by submitting snow and avalanche conditions. You can also call us at 801-524-5304, email by clicking HERE, or include #utavy in your tweet or Instagram.

To get help in an emergency (to request a rescue) in the Wasatch, call 911. Be prepared to give your GPS coordinates or the run name. Dispatchers have a copy of the Wasatch Backcountry Ski map.

Backcountry Emergencies. It outlines your step-by-step method in the event of a winter backcountry incident.

If you trigger an avalanche in the backcountry, but no one is hurt and you do not need assistance, please notify the nearest ski area dispatch to avoid a needless response by rescue teams. Thanks.

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DAWN PATROL Hotline updated daily by 5-530am - 888-999-4019 option 8.

TWITTER Updates for your mobile phone - DETAILS

UDOT canyon closures: LINK TO UDOT, or on Twitter, follow @UDOTavy, @CanyonAlerts or @AltaCentral

Utah Avalanche Center mobile app - Get your advisory on your iPhone along with great navigation and rescue tools.

Powderbird Helicopter Skiing - Blog/itinerary for the day

Lost or Found something in the backcountry? - http://nolofo.com/

Ski Utah mobile snow updates

To those skinning uphill at resorts: it is critical to know the resort policy on uphill travel. You can see the uphill travel policy for each resort here.

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This information does not apply to developed ski areas or highways where avalanche control is normally done. This advisory is from the U.S.D.A. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always exist.