Avalanche Advisory
Advisory: Moab Area Mountains Issued by Eric Trenbeath for Sunday - February 16, 2014 - 6:52am
bottom line

The danger for wet slide activity will rise to CONSIDERABLE as the day heats up. There is also a CONSIDERABLE avalanche danger on slopes steeper than 35 degrees that have recent deposits of wind drifted snow. This danger is primarily located on, but not limited to, upper elevation slopes with N-E-SE aspects. There also remains a CONSIDERABLE danger for triggering a buried persistent slab. Considerable danger means that natural avalanches are possible and human triggered avalanches are likely. Back country travelers will need to practice safe travel techniques, staying off of, and out from under steep terrain.




current conditions

La Sal Mountains

Temperatures at 10,000' dipped low enough for a for a re-freeze overnight, but warm temperatures during the day have turned the snow pack into an un easy combination of wet snow, and wet snow siting on top of loose facets at low to mid elevations. Upper elevations still hold dry snow on shady slopes, but the wind has affected exposed, westerly aspects. All sunny aspects are crusted over. Ridge top winds have been on the increase, averaging close to 30 mph and gusting in to the 40's from the south. It is currently 33 degrees at 10,000', and 25 degrees on Pre-Laurel Peak. There is 50" of snow on the ground in Gold Basin, and 30" at the Geyser Pass Trailhead.

Winds and temperature on Pre-Laurel Peak (11,705')

Temperature and new snow totals in Gold Basin (10,050')

Total snow depth and temperature near Geyser Pass Trailhead (9850')

Abajo Mountains

Low snow conditions still remain in the Abajo Mountains with lower elevations turning into a soupy mess of wet snow, and wet snow on facets. The snow pack depth averages between 18" and 36", but some sun and wind exposed slopes are showing bare ground. For more information, see this report Winds on Abajo Peak are averaging in the teens with gusting in mid 20's. It is currently 26 degrees.

Winds and temperature on Abajo Peak (11,330')

Snow totals at Camp Jackson (8968')

recent activity

I've been able to get out and look around at things and follow up on reports, and we did have a natural avalanche cycle last weekend. Many natural storm snow avalanches occurred, but a few slides managed to step down into older, buried facets. No new activity has occurred in almost a week, but the slopes that ran, contrasted with those that didn't illustrate the tenuous balance we are in. Most notable was a large slide on the Horse's Head in the Abajo Mountains, and a large slide in Upper Horse Creek in the La Sals. Click here to see some of the avalanche reports.

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

Recent wind slab development continues to be a problem at upper elevations, where steady, westerly winds continue to deposit new drifts of snow. Triggering one of these slabs would be dangerous enough, but they also wield the potential to step down deeper into the snow pack causing a large, and possibly un-survivable avalanche.

The following photo illustrates persistent wind loading:

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

We are in a tenuous balance out there. The underlying snow pack is very weak, and yesterday, my partner Ed Grote, and I observed several large collapses indicating that the pack has yet to adjust to the most recent load. The possibility of triggering a deep, persistent slab is a very real and present danger.

Photo illustrates cracking in the snow of the past 10 days that has consolidated over top of very weak snow.

Snow pit illustrates weak layers in the snow pack with a very clean shear on mid level facets. CT12 Q3

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

With a decent freeze overnight the snow has locked up a bit. The danger for wet slide activity will rise today as daytime heating progresses. Stay off of and out from under steep slopes as the day heats up, and be alert to signs of instability such as roller balls, wet sluffs, and soft, sloppy snow up over your boot tops.

Photo illustrates wet roller balls as a sing of instability:

Photo illustrates a snowmobile triggered slope collapse of wet snow over weak, faceted, sugar snow.

weather

Today will be mostly cloudy with high temperatures again rising to near 40 degrees. SW winds will continue to blow in the 20-30 mph range along ridge tops with gusts to 40 mph. Tomorrow will be sunny, but slightly cooler, and continued windy.

general announcements

OBSERVATIONS: If you are out and about in the mountains, I'd love to know what you are seeing so please SUBMIT OBSERVATIONS  You can read current OBSERVATIONS HERE.

LUNA GROOMING INFORMATION: Trails are groomed and are in excellent shape. Get on them on the morning for fastest conditions.

ROAD CONDITIONS: The road is snow packed but clear.

UAC MOBILE APP: Get your advisory on your iphone with this app