Moab Avalanche Advisory

Forecaster: Max Forgensi

SPECIAL ANNOUNCEMENT

Friday's tour verified wind transport and wind slab sensitivity. The advisory is still valid for Saturday with little to no change.


BOTTOM LINE

Danger by aspect and elevation on slopes approaching 35° or steeper.
(click HERE for tomorrow's danger rating)


Danger Rose Tutorial

The Bottom Line for today will be an Avalanche Danger of MODERATE with pockets of CONSIDERABLE at all elevations and aspects for new wind slabs and persistent slabs located on slopes greater than 35 degrees.

Be especially careful of cross loaded slopes, and trigger points such as convex rollovers and near shallow buried rocks and trees. There's good skiing out there, just hold the throttle back for a little longer.


CURRENT CONDITIONS

Thursday's storm added 3" of snow at the Geyser Pass TH, 5" in Gold Basin and more up higher in the La Sal Mountains. The Abajo Mountains missed the storm. Since the light density (6%) snow fell yesterday, the great NNE-NE wind blew for six hours overnight with averages between 15 and 30 mph. Above tree line locations will be affected by wind transported snow. Click HERE for information on the snow pack BEFOREthe wind event.

LUNA volunteers are heading up today to groom the entire track, and I'll be San Juan County will not be too far behind to plow the road. 4WD will be necessary in the morning.

The conditions in the La Sal mountains are at their best of the season! With 105 cm of snow at the Gold Basin stake, a fair bit of ground hazards are now covered, especially in upper elevations. These hazards could have acted as anchors in some places, now covered, larger pieces of snow are connected and can produce larger avalanches with future weather events.


RECENT ACTIVITY

Yesterdays lack of Mother Nature's clues was very disturbing. Looking at the structure of the snow in most places, it has the characteristic of having stronger snow over weaker snow...a recipe for avalanches. Over half of the snow still consists of mature faceted grains, and stability tests are sudden planar with a Shear Quality of 1. Failures just "cash register" out.

Snow and wind events have kept the mountains under a critical threshold for natural avalanche activity. There is Considerable danger out there in avalanche terrain, what is missing is a trigger; and in this case the trigger may be you or someone in your party. Managing your group and inner human factors will mitigate risk. The mountains will be there well beyond our existence and there will be a better time to descend your favorite or desired line.


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

The wind event is less than 24 hours old and any new wind slabs formed over Thursday night will be very sensitive on Saturday. These wind slabs will more than likely be in the soft slab category and between 12-24 inches thick at and above tree line on leeward sides of slopes and ridges, perhaps cross-loaded in below tree line locations.


THREAT #2

WHERE PROBABILITY SIZE TREND
      Over the next 48 hours.

The Danger Rose looks like a Yellow Dragon with Orange Spots. There are locations in which a back country traveler will have a "probable" chance of triggering an avalanche due to these persistent slabs. Look at the facts folks:

1. Shallow snow pack with the lower half faceted, with slab conditions overlying these basal facets

2. High Quality 1 Sudden Planar Shears.

3. Moderate stability tests. These can give "false stable" for those looking for a reason a slope is safe.


MOUNTAIN WEATHER

@ 10,000' in Gold Basin, La Sal Mountains, Utah.Saturday: Mostly sunny, with a high near 24. East wind around 5 mph becoming calm. Saturday Night: Mostly clear, with a low around 18. Calm wind becoming south southeast between 5 and 10 mph. Sunday: Mostly sunny, with a high near 31. South southwest wind between 5 and 10 mph.


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 occur.


This advisory provided by the USDA Forest Service, in partnership with:

The Friends of the Utah Avalanche Center, Utah Division of State Parks and Recreation, Utah Division of Emergency Management, Salt Lake County, Salt Lake Unified Fire Authority and the friends of the La Sal Avalanche Center. See our Sponsors Page for a complete list.