Sun, sun, and more sun means wet loose cycle

Location Name: 
Forecaster Observation - Snowshed/ Essex Creek, Flathead Range
Observation date: 
Sunday, March 11, 2018 - 16:30
Is this an Avalanche Observation: 
Yes
Observation made by: Forecaster

Location

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Quick Observation

Toured on Snowshed Mountain and in upper Essex Creek to monitor ever-developing wet loose cycle and monitor snow quality on shady aspects after two consecutive warm days.

  • Found supportable, dry, and cool snow on shady aspects (NW - NE)
  • Solar aspects at mid/ lower elevations were moist and producing numerous rollerballs
  • Southern aspects at mid/ lower elevations started producing wet loose debris by mid-afternoon (1 - 3 pm)
  • High, thin cloud cover late-morning into mid-afternoon helped keep temperatures from warming rapidly and delayed wet loose cycle
  • Seems that upper elevations still need a full day of sun and warm temps to start producing wet loose debris
  • Evidence of natural wind slabs after our last storm cycle was less noticeable in this zone compared to where I traveled to the north yesterday (Tunnel Ridge)
  • By late afternoon, sunny aspects that moved into the shade were quickly transitioning back to the re-freeze cycle
Snowpack, Avalanche, Weather Images: 
Travel Details
Region: 
Flathead Range - Middle Fork Corridor
Route Description: 

Izzack Walton ski trails to Snowshed Mountain up to 7600'.

Activity: 
Skiing
Snowpack Details
Snowpack and Weather Details: 
Hide Terrain
Elevation of observation: 
3500-5000 ft
5000-6500 ft
Above 6500 ft
Aspect(s) of observation: 
N
NE
E
SE
S
SW
W
NW
Red Flags: 
Rollerballs / pinwheels
Persistent Weak Layers: 
On the surface
New Snow in the past 24 hours: 
0.00in.
More comments about the snowpack and weather: 
Widespread surface hoar formation on both sunny and shady aspects (2-5 mm) at mid/ upper elevations. Sun was cooking surface hoar by mid-day on sunny aspects but stayed preserved and upright on shady aspects.
Avalanche Details
Avalanche Details: 
Date and Time of Avalanche: 
Sunday, March 11, 2018 - 15:00
Avalanche Type: 
Wet Loose
Failure Plane/Weak Layer: 
Within storm snow
More information or comments about the avalanche: 

Numerous wet loose avalanches (D1-1.5) observed primarily on southwest to southeast aspects by the afternoon. Easterly aspects didn't appear to warm enough to produce more than rollerballs due to high cloud cover. Didn't observe any activity on west aspects by the time we exited the area.

Hide Trigger
Trigger: 
natural
Hide Terrain
Aspect: 
South
Starting Elevation: 
near-treeline
Hide Size
Destructive Size: 
D1.5
Relative Size: 
R2 Small
Avalanche Length (Vertical Run): 
500ft.
Hide People Involved
Number of people caught: 
0