Observation: Millcreek

Observation Date
02/1/2018
Observer Name
John Mletschnig

Region:

Location Name or Route
Mill Creek
Weather
Sky
Overcast
Wind Direction
West
Wind Speed
Moderate
Weather Comments
Breezy most of the day with a little snow moving on the surface in the valleys and up high. No precip.
Snow Characteristics
Snow Surface Conditions
Powder
Faceted Loose
Wind Crust
Melt-Freeze Crust
Rain-Rime Crust
Snow Characteristics Comments

Northerly trees held sheltered creamy powder. Slopes out of the trees had a thin rime crust on northerlies. Southerlies had a melt crust surface form. Terrain on the west half above 10500' is very stripped by winds. So much of the snowpack is facets that sledding around is challenging off trail as well as taking your skis off without plunging to your waist.

Red Flags
Red Flags
Recent Avalanches
Wind Loading
Poor Snowpack Structure
Red Flags Comments
There are a lot of large facets in the lower portion of the snowpack on northerly terrain. Where there is a connected slab on top there are very likely problems at hand. Remotely triggered slideoff Deadman Pass observed from a couple days prior which failed deep adn fairly wide, R3D3.
Avalanche Problem #1
Type
Persistent Slab
Problem #1 Comments

There is a huge amount of weak snow out there right now on W-NW-N-NE-E-SE above 8000'. The question is whether terrain has a slab on top of the weak snow or not. Areas with wind loading are the most suspect to have a connected overlaying slab. In the lower snowpack there is a rain crust with large facets on top of it. Also of note was a buried surface hoar layer found buried down 35cm from the surface in protected terrain above 10K. The snowpack is interesting to look at for sure.

Snow Profile
Aspect
North
Elevation
10700
Slope Angle
18
Comments

ECTN15 (propagated half way across column) down 35cm on Surface Hoar. No result on deeper layers... I suspect that this may have had a bit to do with how deep of a spot it was where we dug: HS155cm. Depth hoar grains in lower snowpack were 3-8mm.

Pit with obvious layer (surface hoar 2-4mm) buried 35cm down.

Likely remote triggered slide from sledder a couple days ago (see avalanche observation)

Very little snow on westerlies above 10500'. Clear blown out of there.

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