Observation Date
2/1/2013
Observer Name
Nate H-S, Kent C.
Region
Logan
Location Name or Route
Beaver Envy - south side
Weather
Sky
Broken
Precipitation
Light Snowfall
Wind Direction
West
Wind Speed
Strong
Weather Comments
Wind picked up as the Thursday-Friday front pushed over the region. Snow was being visibly transported. Wind and transport shifted from L/L on the ground to M(I)/S on the ridge at 8300-8400 feet.
Snow Characteristics
New Snow Density
Medium
Snow Surface Conditions
Dense Loose
Snow Characteristics Comments
Wind deposits were abundant on the leeward side of trees. The east ridge was scary loaded and settled but did not propagate remotely. Anything facing Beaver Mountain from mid-slope 210-260 degrees had the potential to be wind-scoured and firm. Conditions were highly variable. This may change with the predicted warming and low winds, but as of Friday 1 FEB, terrain choices were very important to manage this risk.
Red Flags
Red Flags
Wind Loading
Cracking
Collapsing
Poor Snowpack Structure
Red Flags Comments
Massive wind deposits were settling and collapsing under a skier's weight. We didn't propagate anything as we stayed on slopes <30 degrees all day.
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Decreasing Danger
Problem #1 Comments
Lots of snow had moved the night of 31 JAN into 1 FEB. We experienced everything from 100+cm drifts to scoured terrain. Most slabs were depositing on the leeward side of trees and ridges, making the west side of the compass *highly variable*. You could skin or ski a line and go onto the leeward (East) side of the trees and pee your shorts upon seeing the collapses and cracks. F/4F snow is sitting deeply on top of fist hard facets that underlie the January rime. As winds die down, this may settle out, but it didn't seem to be happening as of 2FEB.
Avalanche Problem #2
Problem
Persistent Weak Layer
Trend
Same
Problem #2 Comments
The wind slabs are highly reactive right now and would almost certainly move up high at steep angles, potentially stepping down into deeper weak layers like the Christmas facets under the early January rime. This is not a secondary problem, but likely comparable and collinear with the wind slabs at some locales.
Snow Profile
Aspect
West
Elevation
8,500'
Slope Angle
30°
Comments
We did two sets of ECT tests. ECTN14 and ECTN 12 occurred in the recently deposited snow and ECTP19 occurred in the January rime layer that capped the Christmas storm facets. We dropped a ski at ~25lbs of pressure and got a large isolated column to propagate and slide entirely out of the block. Once again, the rime-facet interface failed. These failures occurred at around 65-70cm with a snow height between 90 and 100cm.
Video
Coordinates
