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Observation: Empire Pass

Observation Date
12/7/2023
Observer Name
Graves, Moriarty
Region
Salt Lake » Park City Ridgeline » Empire Pass
Location Name or Route
Empire Pass
Red Flags
Red Flags
Recent Avalanches
Wind Loading
Cracking
Poor Snowpack Structure
Avalanche Problem #1
Problem
Wind Drifted Snow
Trend
Increasing Danger
Problem #1 Comments
We noted lots of snow transport during our drive up to the trailhead and throughout our travels today. Winds were moderate with strong gusts out of the west and intensified throughout the morning. They shifted to the north around noon. We observed wind-loading and hard slab of wind-drifted snow on northerlies while wind eroded snow on ridgelines and exposed areas. Skiing on a couple of wind loaded test slopes resulted in some localized cracking but no collapsing. The cracking we did observe failed within the freshly wind-drifted snow right under our skis. We dug on a windloaded, NW facing slope, which had a 20cm thick pencil hard slab of recently wind-drifted snow.
Avalanche Problem #2
Problem
Persistent Weak Layer
Trend
Increasing Danger
Problem #2 Comments
Tests in our pit produced an ECTN5 at 61cm within a windloaded layer and and ECTP11 at 10cm. The failure plane at 10cm occurred at the interface of a sturdy melt-freeze crust and a faceted layer above the crust, which held the weakest snow in the snowpack. We've been seeing similar results at this failure plane in other, similar areas over the past week.
Snow Profile
Aspect
Northwest
Elevation
9,000'
Comments
Winds and precipitation starkly intensified throughout our travels this morning. When the wind shifted north around noon everything instantly became rimed including our gear, pit walls, and ourselves. We noted some graupel in the top few centimeters of the snowpack. Our layer of most concern is at 10cm and is made up of large, weak, faceted snow above a melt-freeze crust. My biggest takeaway from today is that the sustained winds from yesterday and today have created a significantly harder slab above the weak snow closer to the ground than I've observed in similar areas in the last week.
Today's Observed Danger Rating
None
Tomorrows Estimated Danger Rating
None
Coordinates