Observation: Maple Hollow

Observation Date
03/19/2018
Observer Name
Toddeo

Region:

Location Name or Route
Pahvants - Maple Hollow
Weather
Sky
Clear
Wind Speed
Calm
Weather Comments
Calm warm day
Snow Characteristics
New Snow Depth
10"
New Snow Density
High
Snow Surface Conditions
Powder
Dense Loose
Snow Characteristics Comments

An additional 2" of Graupel fell after I left the area yesterday.  Some wind affected snow on an exposed north facing ridge line that separates north from west facing aspects.

On west aspects below 8,500', my max today, the snow was well bonded to a pencil hard crust up to 10" thick.  No sluffing or movement on 40 degree rollovers.  The dense snow helped prevent bottom feeding and held up well to the sun/warmth.

Some soft wind slabs on the ridge up to 12" thick.

Red Flags
Red Flags
Wind Loading
Poor Snowpack Structure
Red Flags Comments
Wind loading is a new red flag, due to the soft wind slabs up to 12" which broke easy on pole columns. The poor snowpack structure is related to basal facets which are still hanging around. I did not venture onto north aspects today except to pole probe, but assume they still exist. I am still treating Norths with caution. The basal facets I looked at on west aspects were damp and looked like they have been damp for awhile (photo below). they were still loose (fist).
Avalanche Problem #1
Type
Persistent Slab
Trend
Same
Problem #1 Comments

I treated upper elevations norths as they have considerable hazard, not taking any chances.

Avalanche Problem #2
Type
Wind Slab
Trend
Same
Problem #2 Comments

Not a real widespread issue but worth mentioning.

Snow Profile
Aspect
Northwest
Elevation
8000
Comments

HS = 26"

10" sitting on top of a 10" thick pencil hard crust.  Underlain by 6" of loose wet facets or forms formally known as facets.

Photos below:

1. Wet facets

2 & 3. Graupel surface, there is also some facets which do not show up well.

 

Photos below:

1. Terrain at 8,200'.  I avoided the slope on lookers left, this slope is a bit over 35 degrees and has facets at the base of the snow pack similar to what is being reported at skyline.  The last two winters I was able to ski this slope at will by this time of the year.  This year I am not going near it right now.

2.  Todays terrain, new snow over a solid crust, a safer alternative.

3. Trailhead conditions, yesterday we were skiing on this road.

I would call The hazard in the NW facing terrain, where underlain by the solid crust moderate.

I would call the hazard considerable on steep north facing slopes above 8,000'.

Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable
Snow Profile Coordinates