Observation: 10420

Observation Date
02/27/2018
Observer Name
Evelyn

Region:

Location Name or Route
10,420
Weather
Sky
Overcast
Wind Direction
Southwest
Wind Speed
Light
Weather Comments
Temperatures in the twenties and low thirties felt down right balmy compared to last week.
Snow Characteristics
Snow Surface Conditions
Dense Loose
Wind Crust
Snow Characteristics Comments

Wind slabs, hard wind slabs. Though there is good, dense powder on wind sheltered, untracked slopes.

Red Flags
Red Flags
Wind Loading
Poor Snowpack Structure
Red Flags Comments
Dissappointed to see no recent natural avalanche activity.
Avalanche Problem #1
Type
Wind Slab
Trend
Decreasing Danger
Problem #1 Comments

Pencil hard wind slabs, haven't seen many of these this winter.  Widespread along ridge lines, scattered off ridge lines in open areas.  An entirely different beast than the soft slabs we've mostly had this winter.  They seem supportable, yet tend to break above you and often not on the first person.  They also often take longer to stabilize.

Photo below - pencil hardness (not one finger hardness)

Photo below a windward slope, scoured down to the Feb 18th dirt layer.  A measure of how much snow was eroded and transported.  30 to 40" at the upper elevations.

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

The snow pack has multiple weak layers, which vary by aspect and elevation.  In deeper snowpack areas, it's more likely to trigger one of the upper weak layers.  In shallower snowpack areas, slides were breaking near the ground the past few days.

Example of spatial variability and how the snow pack can change rapidly over very short distances.

Snow Profile
Aspect
Northwest
Elevation
10100
Slope Angle
32
Comments

Looking at the upper layers in the snow pack.  This was in a non-wind loaded area, no hard slab on top.  Weakest layer of concern was small facets about an inch above the dirt layer from Feb 18th.  There was also a weak layer within the newer snow, that I'd expect to strengthen.

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