Observation: Primrose Cirque 12/20/2011

Observer Name:

Nalli

Observation Date:

12/20/2011

Region:

Provo
Provo Canyon
North Fork
Primrose Cirque

Location or Route:

Primrose Cirque

Weather

Sky:

Scattered

Wind Direction:

Southwest

Wind Speed:

Strong

Weather Comments:

Sunny and bright with some high status clouds moving in. The valleys below 6000' have been socked in with a thick inversion/fog for the last many days now. There is lots of moisture in this layer and at times it has been precipitating pollution in the valley bottoms. Only one or two cm of new snow has accumulated but the real effect has been the influx of moisture to the elevation band above this "bath tub ring". The surface hoar that has grown between 6000'-8000' is impressive.

Snow Characteristics

Snow Surface Conditions:

Faceted Loose

Snow Characteristic Comments:

Most of the snowpack is faceted in some way or another. It makes for some load, sugary, fun skiing where you can find enough depth to not hit all the rocks and brush lurking below.

snow_profile_location:

Comments - Photos - Videos (group 1)

Over the last week the surface hoar at Aspen Grove has grown to 4-7mm on average. As you gain elevation in Primrose the SH gets smaller. This may be due to the moisture source in the inversion that keeps creeping up and down the canyon and never really gets any higher than about 6000'.

Comments - Photos - Videos (group 2)

SH of this size can be found from 6500' to about 8000' on all the shady undisturbed slopes around Primrose. It has been mentioned that this SH may really be inconsequential because the layer below it is so soft and its really all just one big pile of facets anyway that will surely avalanche with the next load. Big Facets - Surface Hoar... what's the difference at this point, its all garbage.

Comments - Photos - Videos (group 3)

In some locations it has grown close to potato chip size. This crop was found closer to the parking lot. Not sure what caused this to get so big in this locale.

Comments - Photos - Videos (group 4)

Like Kowboy was seeing in Days Fork today, after about 10cm of very weak snow at the surface there is a much more dense wind crust capping yet more facets down to the ground. Its very likely that the weakest snow at the surface will avalanche as soon as we get the next load, but this crust is stout enough to hang in there for longer allowing a deeper slab to build up. That is if it ever actually snows.

Observed Danger Rating:

Low

Forecast Danger Rating:

Low