Observation: Double Hill

Observation Date
12/14/2012
Observer Name
Ted Scroggin
Region
Uintas
Location Name or Route
Whitney Basin-Double Hill
Weather
Sky
Overcast
Precipitation
Light Snowfall
Wind Direction
South
Wind Speed
Light
Weather Comments
Overcast skies till 1300 when light snow began. Winds were generally light from the south/southwest.
Snow Characteristics
Snow Surface Conditions
Powder
Dense Loose
Wind Crust
Snow Characteristics Comments
Lower elevation snow conditions (below 9,000) are still thin with lots of obstacles. Upper elevation riding has improved with many places filled in and riders today were talking of a mostly supportable base.
Red Flags
Red Flags
Wind Loading
Cracking
Collapsing
Poor Snowpack Structure
Red Flags Comments
Recent strong winds have really worked over the snowpack, creating some stiff wind slabs along the ridgelines and even down into the flats. Many collapses were heard today as I traveled around the Whitney Basin.
Avalanche Problem #1
Problem
New Snow
Trend
Increasing Danger
Problem #1 Comments
With snow depths 2-3' around the Whitney area, the concern is the weak faceted snow that formed back in November that is now about in the middle of the snowpack. Where the winds have deposited a hard slab overloading this weak layer are the more likely places an avalanche could be triggered.
Avalanche Problem #2
Problem
Persistent Weak Layer
Trend
Same
Problem #2 Comments
Today's wind slabs were reactive to the weight of a person, cracking out 10-12" deep, these were mostly found in the more wind exposed terrain. These wind slabs have relaxed a bit and not as sensitive as a day or two ago.
Comments
I was finding some of the wind slabs to be reactive to the weight of a person in the more wind exposed terrain. Second photo: winds have been stripping snow from the southerly aspects and depositing it onto the northerly facing slopes.
Generally about 2-3' of snow in the Whitney Basin with fairly good coverage, but some stumps and rocks are still thinly covered. Second photo: decent riding can be found in the meadows and grassy areas.
I observed this natural avalanche from a distance on a very steep north facing slope with likely weak snow that was overloaded from recent strong south/southwest winds. I do not know how recent this slide is?