Avalanche Advisory
Advisory: Salt Lake Area Mountains Issued by Evelyn Lees for Friday - December 9, 2016 - 7:08am
bottom line

The Avalanche Danger is rising, and backcountry travel in changing conditions is challenging. This morning, the danger is CONSIDERABLE on all steep upper elevation slopes, and all mid and upper elevation slopes with fresh drifts of wind blown snow. Other mid and lower elevations slopes have a MODERATE danger.

Small wet sluffs are possible at the mid to lower elevations, and roofs may shed their snow into deep piles this weekend.

Those with good avalanche and terrain evaluation skills can still head out and enjoy the new snow. Stay on lower angle terrain - slopes of about 30 degrees or less, without steep slopes above you.




avalanche warning

THE FOREST SERVICE UTAH AVALANCHE CENTER IN SALT LAKE CITY HAS ISSUED A BACKCOUNTRY AVALANCHE WARNING.

* TIMING...IN EFFECT THROUGH 600 AM SATURDAY.

* AFFECTED AREA...THE MOUNTAINS OF NORTHERN UTAH INCLUDING THE WASATCH RANGE...BEAR RIVER RANGE...AND THE WESTERN UINTA MOUNTAINS.

* AVALANCHE DANGER...THE AVALANCHE DANGER WILL BECOME HIGH TODAY AND REMAIN ELEVATED THROUGH THE WEEKEND.

* REASON/IMPACTS...DENSE HEAVY SNOW COMBINED WITH STRONG WINDS WILL CREATE WIDESPREAD AREAS OF UNSTABLE SNOW AT THE MID AND UPPER ELEVATIONS. BOTH HUMAN TRIGGERED AND NATURAL AVALANCHES ARE CERTAIN. STAY OFF OF AND OUT FROM UNDER SLOPES STEEPER THE 30 DEGREES.

current conditions

Dense snow is falling in the mountains. 24-hour totals as of 6 am are in the 4 to 6” range, with up to ¾ of an inch of water. There were isolated reports of riming and freezing rain yesterday, which may have affected the mountain wind sensors. Punchy or inverted conditions are likely today

Temperatures have warmed over 25 degrees in the past 24 hours, and are now in the mid to upper 20s, with a few low elevation stations in the 30s. The winds are cranking from the southwest – at times averaging 20 to 30 mph at the mid elevations, with averages up to 40 mph averages and gusts to 60, across the highest peaks.

recent activity

A backcountry avalanche yesterday shows how sensitive the new snow is – in Mineral Fork, BCC, a sluff off a rock band triggered a shallow 50 foot wide new snow slide that had enough punch to take a person for a slow motion ride a short ways down the slope. Observation HERE.

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

Both natural and human triggered avalanche will be likely today on steep, wind-drifted slopes at both the mid and upper elevations. Drifts up to a foot deep have formed, and will be most widespread along ridge lines facing northwest through southeast. As you travel through the backcountry, use small test slopes to check the sensitivity and depth of the cracking drifts. In more isolated areas, buried wind and sun crusts could produce a few deeper slides today.

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

There was widespread weak surface snow on all aspects and almost all elevations before this storm, and the new snow will bond poorly and be very reactive. It will be easy to trigger new snow sluffs and shallow soft slabs on steep slopes, and these could run long distances in continuously steep terrain. As they entrain snow, the resulting debris piles could be surprisingly deep. Again, jump on small test slopes to get a feel for the sensitivity.

At and below the rain/snow line, it will be possible to trigger small wet sluffs in the wet new snow and rain soaked old snow. Avoid travel in terrain traps, such as gullies, creek beds and below road banks, where even a small side can pile up debris.

weather

A moist westerly flow will result in periods of mountain snow through at least early Sunday. An additional 2 to 6” of warm, dense snow is expected today, with the rain/snow line rising to 7,000’. The southwesterly winds will remain strong, averaging 20 to 30 mph at the mid elevations, and up to 40 mph with gusts in the 50’s across the highest peaks. Temperatures will warm into the upper 20s at 10,000’ and to near freezing at 8,000’. This is a long duration storm, with more snow is on the way through the weekend.

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.