Observation: Willows

Observation Date
1/7/2019
Observer Name
Fink and Slack
Region
Salt Lake » Big Cottonwood Canyon » Willows
Location Name or Route
Main Willow
Red Flags
Red Flags
Recent Avalanches
Heavy Snowfall
Wind Loading
Poor Snowpack Structure
Avalanche Problem #1
Problem
Wind Drifted Snow
Trend
Increasing Danger
Problem #1 Comments
Significant and ongoing wind drifting throughout the day. Snow surface becoming more consolidated in all but the most sheltered areas, with rapid formation of 4f+ wind slab ~10-15cm thick during our 3 hour tour.
Avalanche Problem #2
Problem
New Snow
Trend
Same
Problem #2 Comments
New snow totalling about 2 ft in favored/sheltered areas. Moderate density with mild density inversion and apparently good adhesion to old snow surface. Minimal sluffing in all but the steepest areas.
Comments
Free microdermabrasion out there today.
Multiple small natural slabs observed heading up BCC in the mineral slabs area had us on alert, as did the swirling winds. No cracking or collapsing observed on our conservative route.
Skies overcast with occasional sucker holes. Precip continued throughout the morning: light accumulation of rimed dendrites with intermittent squalls of grauppel to pelt the face and reduce wrinkles. Winds were steady 20-30 mph gusting 50 out of the S/SW.
LOTS of wind transport today. Locally variable aspect, with loading onto westerly aspects along the ridge above willow knob, while the main willow ridge line was getting blown into the monitors. Didn't muck with the big, pregnant wind drifts along the ridges, as travel on the windward scoured snow was much easier.
Surprised to not observe cracking and collapsing, but pleasantly so. Riding conditions were good, though snow density made lower-angle slopes more challenging to ride.
Bottom line: storm seems to have overdelivered re: totals, and the winds are wreaking havoc, causing widespread wind effect, scouring, and increasing hazard from wind slab formation on W-N-NE aspects. It will be interesting to see if any of that load can awake the basement facets.
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable
Coordinates