Avalanche Advisory
Advisory: Moab Area Mountains Issued by Eric Trenbeath for Sunday - November 15, 2015 - 6:55am
bottom line

There is a MODERATE danger for triggering a persistent slab 2-3 feet deep on mid to upper elevation terrain, steeper than 35 degrees with a NW-N-E aspect. By tomorrow, this danger will likely increase to CONSIDERABLE. There is also a MODERATE danger for triggering an older, stubborn, as well as recently formed wind slabs in upper elevation terrain where you can detect deposits of wind drifted snow. This danger is also expected to rise to CONSIDERABLE as the storm moves in tomorrow.




current conditions

We are off and running with one of the best starts to a season that I can remember. Last week's storm laid down over 2 feet of medium density snow on top of a base that varied from 6" at Geyser Pass Trailhead, to 18" at upper elevations. It is still very much a shallow, early season snowpack with lots off stumps, rocks, and dead fall lurking beneath the surface, but cautious enthusiasts will be able to find enough snow to slide around on.

There is currently a 32" base in Gold Basin, and 22" at Geyser Pass Trailhead.

Storm snow from last week has settled out considerably, and good powder conditions can be found on shady slopes. A strong sun and temperatures in the 30's have put a crust on low to mid elevation southerly aspects, and above tree line, the wind has damaged some areas.

Winds on Pre-Laurel Peak bumped up overnight into the 20's gusting to 30 mph from the SSE and the temperature up there this morning is 14 degrees. It's 25 degrees at 10,000' in Gold Basin.

La Sal Weather

Wind speeds and temperature at 11,700' on Pre-Laurel Peak.

New snow totals and temperature at Geyser Pass Trailhead.

recent activity

There was some avalanche activity during the last storm on November 10-11. Primarily on N-NE facing slopes the slides ran on the old snow surface with fractures between 2-3 feet deep. A slide from Moab Lanes, on the NE face of Tukno started near the summit as a soft wind slab and then fractured to 200' wide midway down the path sending debris all the way down into Tele-Heaven, and over the cliffs into Tele-Gold. Exxon's Folly also ran, and I observed other snowed in fractures in Middle and Red Snow Cirques.

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

Last week's snow has largely settled into place but it still seems to be making some minor adjustments. Parties yesterday were still reporting collapsing though I didn't observe any myself. A now buried facet layer just beneath the old snow surface still remains, and could be capable of producing an avalanche. Snow pits showed developing facets at the ground level but growth was surprisingly minimal. Nevertheless, given the nature of shallow, early season snowpacks, and without having gathered a wide spectrum of information yesterday, I am still suspect of the early season snow that is now buried under there. For this reason, I would still temper it back, and avoid slopes steeper than 35 degrees with a NW-N-E aspect without carefully assessing the stability. And with another storm on our doorstep, we are going to have an opportunity to test the strength of the underlying snowpack so expect the danger for triggering a persistent slab to rise by tomorrow.

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

In addition to stiff, stubborn, and hard to trigger wind slabs that still remain, increasing winds today will be moving snow around at upper elevations forming fresh deposits of drifted snow on the lee sides of ridge crests and terrain features. Watch for increasing danger today, and especially into tomorrow as the storm moves in.

weather

Look for sunny skies and blustery conditions this morning. Clouds will move into the area this afternoon with a chance of isolated snow showers this afternoon ahead of the next significant storm system to affect our area through Tuesday. We could see another foot or more out of this.

Today

Isolated snow showers after noon. Increasing clouds, with a high near 33. Windy, with a south southwest wind 20 to 30 mph, with gusts as high as 45 mph. Chance of precipitation is 20%.

Tonight

Snow showers likely before 11pm, then snow, mainly after 11pm. Low around 19. Windy, with a south wind 30 to 35 mph, with gusts as high as 55 mph. Chance of precipitation is 90%. New snow accumulation of 3 to 7 inches possible.

Monday

Snow. High near 26. Windy, with a south southwest wind 25 to 30 mph becoming west southwest 15 to 20 mph in the afternoon. Winds could gust as high as 45 mph. Chance of precipitation is 90%. New snow accumulation of 5 to 9 inches possible.

Monday Night

Snow likely, mainly before 11pm. Cloudy, with a low around 11. Blustery, with a north northwest wind 20 to 25 mph, with gusts as high as 40 mph. Chance of precipitation is 70%. New snow accumulation of 3 to 5 inches possible.

Tuesday

A 20 percent chance of snow. Partly sunny, with a high near 18. Windy, with a north wind around 30 mph.

Tuesday Night

A 10 percent chance of snow. Partly cloudy, with a low around 15. Blustery.

general announcements

This signals the start of the official season with advisories posted over the weekends with mid-week updates as conditions warrant. 

The Road to the Geyser Pass Trailhead is plowed but with patches of ice and packed snow. 

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