Observation: Tushers

Observation Date
11/27/2016
Observer Name
Toddeo

Region:

Location Name or Route
Tushers - Puffer Lake to Big Flat
Weather
Sky
Obscured
Precipitation
Heavy Snowfall
Wind Direction
South
Wind Speed
Strong
Weather Comments
Wow, real winter day. Heavy snow (S 5-10) up tp 3 in/hr, about as hard as it ever snows. Wind was moving snow below treeline.
Snow Characteristics
New Snow Depth
18"
New Snow Density
Medium
Snow Surface Conditions
Powder
Snow Characteristics Comments

18" seems about right, snotel confirms this.  There was close to a foot when I arrived at Puffer Lake and an honest 8" in my tire tracks when I left 3 hours later.  About a foot on the road while leaving.  2' on the road when I arrived and it had been plowed less than an hour before that. 

A combination of rimed dendrites, dendrites, pellets, needles and graupel, all of the above.  Right side up, storm started dense.

Red Flags
Red Flags
Heavy Snowfall
Wind Loading
Cracking
Collapsing
Poor Snowpack Structure
Red Flags Comments
HI PI rates, blowing snow, cracking was not as sensitive as expected but cracks ran in the soft new snow up to 20'. One loud collapse. Some road cuts on the way to Big Flat cracked but did not run. I was able to initiate a lot of cracking but everything stayed in place. I was not able to isolate columns or extended columns. half broke in the new snow and the other half on Q1 to Q2 shears on top of the underlying facets. Underlying facets are weak and were observed on most aspects.
Avalanche Problem #1
Type
Storm Slab
Trend
Same
Problem #1 Comments

I stayed mostly in sheltered areas, the primary hazard will be in the new snow.  Storm slab is up to 18" thick as of 1-2 pm today.

Considerable hazard.

Avalanche Problem #2
Type
Wind Slab
Trend
Increasing Danger
Problem #2 Comments

This wold have been #1 if I was in wind exposed areas,

Considerable hazard.  Increasing as the wind and snow continues.

I would also add normal caution for a thin snow pack.

Snow Profile
Aspect
Southeast
Elevation
10300
Slope Angle
10
Comments

HS = 24" 

About 7" of 2mm loose facets sitting on the ground capped by a weak crust (rain?).  The overlying storm snow (HST=16") is divided by ski pole into the basal 6" 4 finger density early portion of the storm (last night) and the upper 10" fist density portion which fell this morning.

Of interest is a reminder that at the high elevations of the Tushers, snow also facets on sunny aspects.

Photo below is a profile on a wind exposed road cut directly above a 40' wide series of natural cracks that did not run.  facets are obvious....Storm snow is about 10-12" here, northwest aspect at 9,800'

Big Flat Snotel HS=27 at 2 pm.

2 photos below of cracking in the new snow.
 

Snowfall was impressive and will settle out to a great early season base.  Drive down Beaver Canyon was exciting with a foot of snow on the road!  Photo below is at the pass (10,000') 4 hours after the road was plowed, deep driving but a heck of a lot safer than the drive back to Fillmore on I-15!

I would expect a natural cycle in the alpine where there is enough snow.  Things looked pretty scoured yesterday.

Overall a considerable hazard.  Any avalanche will likley run to the ground.

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