Observation Date
2/4/2019
Observer Name
Bruce Tremper
Region
Salt Lake
Location Name or Route
Pole Line Pass
Weather
Sky
Obscured
Precipitation
Moderate Snowfall
Wind Direction
Southwest
Wind Speed
Strong
Weather Comments
Working an avalanche class today and we dug snow pits in the flats below Pole Line Pass.
Weather was a howling blizzard all day long with poor visibility, strong winds and grapple stinging your face.
Snow Characteristics
New Snow Depth
10"
Snow Surface Conditions
Dense Loose
Snow Characteristics Comments
This is the second day of graupel accumulation so I'm not certain of the total accumulation, perhaps 1.5 feet with about 8 inches in the past 12 hours. Guard station would have better numbers. Graupel is quite dense and it seems to be sticking together fairly well. I'm sure it's forming wind slabs in lee terrain but we could not get any to react in our tests but we did not get to the ridges.
Red Flags
Red Flags
Heavy Snowfall
Wind Loading
Red Flags Comments
Lots of graupel and lots of weight with more to come. The graupel is sticking together fairly well and not forming wind slabs as much as you would expect from such strong wind and blizzard conditions but it's the deeper weak layers I'm worried about--the old-new snow interface with near surface facets and surface hoar. We did not find any on the southerly aspects where we were but I'll bet there is some activity in the shady terrain where surface hoar and NSF were preserved.
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Increasing Danger
Problem #1 Comments
With all the weight added it seems like it should be overloading the surface hoar and NSF on the shady, terrain. We did not observe any since we were on southerly or flat aspects. I've been out of town for quite awhile so I'm not familiar with the deeper snowpack structure.
Avalanche Problem #2
Problem
Wind Drifted Snow
Trend
Same
Problem #2 Comments
The new wind drifted snow was surprisingly unreactive where we were but with all the blizzard conditions all day there is sure to be some reactive wind drifts in the more exposed terrain.
Comments
A few photos from the avalanche class I was working today. Dedicated students and instructors were digging snowpits in very challenging weather conditions. Weakest layer was the old-new snow interface but usually it would not propagate on ECT, at least where we were digging the pits.
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable
Coordinates
