Avalanche Advisory
Advisory: Moab Area Mountains Issued by Eric Trenbeath for Wednesday - January 11, 2017 - 6:32am
bottom line

The avalanche danger remains CONSIDERABLE in upper elevation wind exposed terrain. The danger is most acute on steep slopes that face N-NE-E, but cross loading has affected slopes on all aspects. Avoid slopes steeper than about 30 degrees that have recent deposits of wind drifted snow. At mid elevations the avalanche danger is MODERATE. Low elevation terrain offers mostly LOW danger.




special announcement

Plowing: Grand County has no plans for plowing today. It appears that most of the snow fell above the parking lot but you may encounter some drifting on the road.

Backcountry 101 Avalanche Course

We will be offering a Backcountry 101 avalanche class on Feb 3, 4. This course will include a night classroom session and a day in the field. Cost is $125 with proceeds to benefit the Utah Avalanche Center Moab. For more information or to sign up go here.
current conditions

One party yesterday described the mountains as having been plastered in styrofoam. Snow totals varied and strong winds dispersed much of it, but 3-8" of very dense, spongy, snow is providing a fun, and at times, interesting snow surface. Above tree line winds have hammered the surface and a rime crust has been added to the mix. In sheltered areas, the spongy snow can almost be described as supportable and even snowmobiles are riding high on it.

The relentless SW winds of the past week took a little break yesterday, but they spiked up again overnight into the 25-35 mph range with gusts into the 50's out of the SSE. It's 14 degrees on Pre Laurel Peak and 28 at the Geyser Pass Trailhead.

Avalanche conditions are tricky and the snow surface isn't talking to us a whole lot. But strong southerly winds have deposited large amounts of snow down slope on upper elevation N-NE-E facing slopes and cross loading has occurred on all other aspects. Buried weak layers of faceted snow are reactive to stability tests, but the dense surface snow more evenly distributes your weight, making it harder for a rider to affect these weak layers. But if you find the right spot, you could quickly find yourself in a slide 2-3' deep. With more snow, and especially wind in the forecast, I'm going to continue to avoid steep, wind loaded terrain.

Check out this report from Dave Garcia.


This Dave Garcia photo illustrates cross loading patterns on Mount Mellenthin. Note the scoured areas alternating with wind loaded areas.


Got rime? (Dave Garcia photo)

Storm totals and temperature in Gold Basin.(10,000')

Wind, temperature and humidity on Pre Laurel Peak.(11,700')

Snow totals, temperature and snow/water equivalent at the Geyser Pass Trailhead. (9600')
recent activity
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

Wind slabs on top of wind slabs exist at upper-mid to upper elevations, and snow has been deposited further down slope than is usual. The danger will be most acute on upper elevation slopes that face N-NE-E, but with winds of this intensity cross loading is a factor and you may encounter wind slabs on all aspects. Suspect smooth rounded pillows and look for cracking in the snow surface. Avoid slopes steeper than about 30 degrees where wind loading has occurred.
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

Just when we were almost out of the woods, a new round of persistent slab problems has presented themselves. Yesterday I found reactive weak layers of buried faceted snow on a NE facing aspect several hundred feet below tree line at 10,600'. Dave Garcia's party found a reactive faceted weak layer under a melt-freeze crust on a south facing slope at 11,600'. A 2' deep wind slab was sitting on top. The layer failed and propagated at 11 under an extended column test (ECTP 11). For a video of those results check out this link.

This weak layer from a snowpit dug on a NE facing aspect at 10,600' failed on a compression test with a score of 6 (CT6 Q1). It failed at 9 and propagated on an extended column test. (ECTP 9).

weather

Today

Snow. High near 24. Windy, with a west wind 20 to 30 mph, with gusts as high as 45 mph. Chance of precipitation is 90%. Total daytime snow accumulation of 3 to 7 inches possible.

Tonight

Snow likely, mainly after 4am. Mostly cloudy, with a low around 16. Breezy, with a west southwest wind 15 to 20 mph. Chance of precipitation is 70%. New snow accumulation of 2 to 4 inches possible.

Thursday

Snow. High near 23. Breezy, with a south wind 15 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 80%. New snow accumulation of 7 to 11 inches possible.

Thursday Night

Snow. Low around 17. Breezy, with a south southwest wind 10 to 20 mph. Chance of precipitation is 90%. New snow accumulation of 7 to 11 inches possible.

Friday

Snow. High near 24. South southwest wind 10 to 15 mph. Chance of precipitation is 90%.
general announcements

Road Conditions: Expect to find accumulating and drifting snow on the road today at the upper end.

Grooming: Trails are scheduled to be groomed this afternoon.

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The information in this advisory is from the US Forest Service which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur.