Avalanche Advisory
Advisory: Moab Area Mountains Issued by Bruce Tremper for Sunday - February 7, 2016 - 6:30am
bottom line

A CONSIDERABLE avalanche danger of human triggered avalanches remains on slopes that did not slide in the last storm that face northwest, north, northeast and east facing slopes. Considerable danger means "Dangerous conditions. Choose conservative terrain." There's a MODERATE danger on any steep slope with recent wind deposits and a MODERATE danger for wet, loose avalanches on steep, sunny aspects.




special announcement

Geyser Pass road update:
The Forest Service has paid a contractor to plow the Geyser Pass road and it's now open again. And they groomed the trail Friday.

current conditions

This is Bruce Tremper, filling in for Eric Trenbeath who should be back Tomorrow. Thanks so much for putting up with me while he was gone.

All the new snow from Monday's big storm settled into a little over a foot deep. The storm deposited relatively dense, rimed snow making it a bit stiff but more recent faceting from the clear sky has loosened it up a bit. There are sun crusts developing on all the sunny aspects.

We got a couple inches of new snow from the little disturbance Friday. Daytime temperatures warmed up to freezing yesterday. It's 16 degrees in Gold Basin this morning with a total snow depth of 71 inches. It's 12 degrees on Pre-Laurel Peak with a light wind from the northwest.

Winds, temperature and humidity on Pre-Laurel Peak

New snow totals, temperature and humidity in Gold Basin

Total snow depth and temperature at Geyser Pass Trailhead

recent activity

I have to admit I'm quite happy that my forecast during the storm was spot on--High danger along with an Avalanche Warning. Most of the avalanche paths on the upper elevation shady aspects avalanched during the storm. There are too many to mention, but we could see lots of activity off Tuk-No, Red Snow Cirque, Middle Cirque, Talking Mountain Cirque and Horse Canyon, to name a few.


It's hard to see the widespread avalanche activity in these photos because many of them ran in the middle of the storm and subsequent snow covered them up. But the debris piles at the bottom give them away.

I took this photo from where I'm doing a fracture line profile on the flank of the big avalanche in Horse Canyon. It was about 1-2' deep and perhaps 200 yards wide.

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

Travis Nauman​'s excellet observation from yesterday confirms what I'm thinking.

Although most of the usual-suspect slopes avalanched during the storm, I noticed no lack of identical-looking slopes that remain hanging, perhaps waiting for a trigger. If you must ski or snowmobile steep, shady aspects, you should do it on something that has avalanched recently and don't provoke the other slopes that did not slide during the storm. The most active slopes during the storm appeared to be "repeater" slide paths that avalanched earlier in the season and the remaining snow was thin and stayed weak due to the temperature gradient metamorphism process.

The profile I dug Wednesday on the flank of the Horse Canyon avalanche looked like a good example of a repeater slide path. The avalanche broke to the ground and on a very fragile layer of large depth hoar crystals. You can see more details in the video advisory from Thursday.

Faceted snow is one of the persistent weak layers, which makes it especially tricky and dangerous because it continues to produce avalanches several days after it's loaded with weight. Also, in my fieldwork Friday in the Abajo Mountains, I still found many areas with collapsing snow and my snow profiles were showing easily propagating fractures. (See the video.) At least for me, I would not be willing to jump into a steep slope that has not slide yet on one of the upper elevation, shady aspects. So I'll continue to call it Level 3 (orange) for a bit longer.

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

You may continue to find fresh wind deposits, which you should always avoid in avalanche terrain (slopes steeper than 30 degrees).

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

It was sunny up above the low Stratus clouds yesterday and temperatures have warmed up enough, and the sun is getting high enough in the sky, that we're getting wet, loose avalanches on some of the steep, sunny aspects. As usual, get off of, and out from underneath steep slopes when they get soggy in the heat of the day.

weather

We have a high pressure ridge building over us for the rest of the week, so we'll continue to have warming temperatures. We should see lots of sun for the next week.

Here's the National Weather Service link to the point forecast for the La Sal Mountains.

general announcements

Road Conditions: Geyser Pass road was plowed Thursday and is open.

Grooming: The trail was groomed Friday.

This is a single-person operation and I can't be everywhere at once.  You can contribute to your own, community avalanche forecast by letting me know what you're finding.  You can view Moab observations here. To post an observation go here.  You can also give me a call on my cell phone at 801-231-4744

To receive this advisory by email go here.

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.