Avalanche Advisory
Advisory: Moab Area Mountains Issued by Eric Trenbeath for Sunday - December 6, 2015 - 6:44am
bottom line

The avalanche danger is generally LOW, but there still may be isolated areas where it is possible to trigger a persistent slab avalanche, primarily on steep, upper elevation slopes that face the north half of the compass. Suspect slopes with more radical terrain and distinctive terrain features such as gullies, rock bands, or convex break overs.




current conditions

It's been a gorgeous few days up in the mountains and today will continue the trend. Temperatures have been steadily climbing up on Pre-Laurel Peak and it is currently a balmy 28 degrees up there. A temperature inversion has set up and it's about 10 degrees cooler in Gold Basin and at the Geyser Pass Trailhead. The mostly light and northwesterly winds of yesterday switched to the southwest in the wee hours of morning and are averaging 15 mph along ridge tops.

The snow surface is turning into a mixed bag of conditions with a variety of sun and wind crusts though soft snow can still be found on shady, sheltered aspects. In my travels I have also noticed that the pack is beginning to lose some of it's supportability, particularly on shady, wooded slopes below tree line, and it won't be long before we are sinking through to the ground in these areas.

Base depth in Gold Basin: 31"

Base depth at Geyser Pass Trailhead: 20"

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

It's looking pretty white up there. Particularly in sheltered areas between 10,000 and 11,000 feet where a base of 3'-4' exists. Extreme upper elevations have seen a lot of wind so a lot of rocks are still exposed.


Even sun exposed slopes are holding decent snow. Note the humps of barely covered rocks in the foreground however. Still good to be cautious.


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

Though the chances of triggering a persistent slab are growing increasingly unlikely, there may still be areas where the perfect combination exists of an old hard wind slab on top of buried, weak, sugary, faceted snow. The most likely areas for finding this problem are on steep, northerly aspects at and above tree line. Slopes with defined terrain features such as gullies, rock bands, or steep, convex break overs warrant extra caution.

Generally speaking, the snowpack is weakening. Sugary, faceted crystals or depth hoar are developing near the ground. Other faceted weak layers exist, and in some cases, faceting is beginning to take over the entire snowpack. This doesn't bode well for the future, and when snow returns, persistent slab problems will likely be reactivated.

weather

A progressive disturbance passing to the north may bring some high clouds to our area this morning but otherwise expect mostly sunny skies today with high temperatures at 10,000' to be in the mid 30's with an increase in south winds later in the day. A storm track on a zonal flow will stay to the north through mid week. By Thursday, the pattern breaks down as stronger Pacific storm system moves into the intermountain west bringing us our next chance at some snow though it appears to again be mainly affecting areas to the north.

Today

Mostly sunny, with a high near 37. Breezy, with a south wind 5 to 10 mph increasing to 15 to 20 mph in the afternoon.

Tonight

Partly cloudy, with a low around 20. West southwest wind 5 to 15 mph.

Monday

Sunny, with a high near 34. West southwest wind 5 to 15 mph.

Monday Night

Partly cloudy, with a low around 17. West wind 10 to 15 mph.

Tuesday

Mostly sunny, with a high near 29. Northwest wind around 10 mph.

Tuesday Night

Partly cloudy, with a low around 20.

Wednesday

Mostly sunny, with a high near 34.

Wednesday Night

Partly cloudy, with a low around 21.

Thursday

A slight chance of snow after 11am. Mostly sunny, with a high near 32.

Thursday Night

A chance of snow. Mostly cloudy, with a low around 14. Breezy.

Friday

A chance of snow. Mostly cloudy, with a high near 20.

general announcements

The Road to the Geyser Pass Trailhead is plowed but snowpacked. 

Grooming equipment is ready and grooming should begin this week!

Thanks for sending in your observations. You can view Moab observations here. To post an observation go here.

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.