Avalanche Advisory
Advisory: Provo Area Mountains Issued by Evelyn Lees for Sunday - February 25, 2018 - 7:15am
bottom line

The avalanche danger is CONSIDERABLE on all steep, upper elevation slopes, especially those with recent wind drifts, and on many steep mid elevation slopes. Other steep slopes have a MODERATE danger. Complex and dangerous avalanche conditions exist – cautious route finding, careful snow pack evaluation and conservative decision making essential.

You will find better and safer skiing and riding conditions on lower-angled wind sheltered slopes. But be aware of what's above you and avoid travel below steep slopes.




current conditions

The fast moving storm is on its way out, after dropping a quick 1 to 3" at the low to mid elevations in the Provo area mountains. This wind blown low-density snow is capping off a week of steady snowfall.


While temperatures are actually above zero this morning, double digits readings are scarce, only to be found at the lowest elevations. Winds have varied from the southwest to northwest during the past 24 hours, reaching significant speeds at times of 25 to 35 mph averages at the mid elevations, and to the north, high peaks have also had 35 mph averages across the exposed higher peaks.

recent activity

Yesterday’s, 5 huge collapses were reported on low angle terrain on Provo peak, by a party that went to 9500’. In the in an area where 2/3’s of the snow pack is old faceted snow.

Excellent recent Provo area observations:

02/24/2018 Avalanche: Provo Peak Provo region Andrew Bentz

02/24/2018 Observation: Mary Ellen Salt Lake region L. Dunn

02/22/2018 Observation: Bobs Knob Provo region Woody

02/21/2018 Avalanche: Provo Provo region Andrew Bentz

Worth noting - in the Salt Lake area mountains, an avalanche was triggered at 9700’ on east facing Raymond Peak, failing on a very thin mid-pack layer of facets sandwiched in between 2 crusts. In addition, numerous small to medium size new snow avalanches and wind drifts were easily triggered.

Photos of east facing Raymond slide - Gagne left, Hardesty right.

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

Periods of significant winds the past 24 hours have built drifts onto a variety of aspects, most failing on the low-density snow as a weak layer. While the newest wind drifts will be easy to identify – rounded, smooth pillows of snow - yesterday’s wind slabs are now hidden under the new snow. Cracking of denser snow is sometimes an indication that you have hit a wind slab.

Cornices have continued to grow along the mid and upper elevation ridge lines. They often break back further than expected, so give them a wide berth and avoid travel below them.

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

On some slopes, the faceted layers in our snowpack may have reached a breaking point. These deeper slides could be 2 to 3 feet deep, and are most likely to break on a mid-pack faceted weak layer or on the very weak facetes near the ground. Any smaller triggered slide – such as a wind slabs or sluff – has the potential to step down to one of these deeper weak layers. Cracking and collapsing are bulls-eye clues to instability, but these clues may not be present, and snow pit tests are proving to be unreliable.

Here is a glimps of the shallow and weak Provo area snowpack from Thursday, February 22nd. Almost 50% of the snowpack is weak, sugary snow at this 8700' spot.

A great video worth watching, as parts of the Provo area mountains have a similar snowpack. Trent’s video from 8,000' on a north facing slope in Broads Fork highlighting the shallow snowpack issue.

Avalanche Problem 3
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 24 hours
description

Storm snow soft slabs and loose snow sluffs can be triggered today on many steep slopes.

weather

This morning’s snow should taper off by around noon, with skies partially clearing. Temperatures will warm into the teens and low 20s. The westerly winds will remain brisk and gusty – at times averaging 25 mph at the mid elevations and 30 mph at the upper elevations. Increasing clouds and southwesterly winds tonight, with temperatures in the teens. Another small storm Monday night into Tuesday.

general announcements

CLICK HERE FOR MORE GENERAL INFO AND FAQ

The UAC has new support programs with Outdoor Research and Darn Tough. Support the UAC through your daily shopping. When you shop at Smith's, or online at Outdoor Research, REI, Backcountry.com, Darn Tough, Patagonia, NRS, Amazon, eBay a portion of your purchase will be donated to the FUAC. See our Donate Page for more details on how you can support the UAC when you shop.

Benefit the Utah Avalanche Center when you buy or sell on eBay - set the Utah Avalanche Center as a favorite non-profit in your eBay account here and click on eBay gives when you buy or sell. You can choose to have your seller fees donated to the UAC, which doesn't cost you a penny

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 occur.