Observation: Birthday Chutes 11/24/2010

Observer Name:

Bruce Tremper

Observation Date:

11/24/2010

Region:

Birthday Chutes
White Pine
Little Cottonwood Canyon
Salt Lake

Weather

Weather Comments:

Very cold, perhaps -10 F with moderate wind. Down coat, face mask, mittens mandatory. Partly cloudy with wispy clouds around mountains and ice fog.

Snow Characteristics

Snow Characteristic Comments:

With such cold temperatures, snow was stiff, squeeky and slow, but was creamy, nice, somewhat rimed powder. I broke a trail up White Pine most of the way, surprisingly no one there. Probably too cold.

Red Flags

Wind Loading

Cracking

Red Flag Comments:

Lots of evidence of wind loading along the upper elevation ridges. Where we were just under 10,000', we were just getting into the wind loaded terrain and the surface snow was a little cracky, but not reactive. Very cold temperature probably keeping things stiff and stubborn.

I did not see any evidence of avalanche activity in the upper bowl. I figured with all the south and southwest wind, there must have been some wind slab fractures on the north facing slopes. They could have easily been filled in by subsequent wind, but I did not see any debris either. But with the dense, stiff, cold snow and cold temperatures, I did not break trail into the upper bowl for a closer look.

Primary Concern

Primary Concern:

Wind Slabs

Probability:

Moderate

Aspect:

East

Southeast

South

Elevation:

High

Trend:

Less Dangerous

Primary Concern Comments:

Lingering wind slabs along the upper elevation, wind exposed terrain, but cold temperatures are keeping them stiff and stubborn. Danger was probably low in the area where I was--just down out of the wind affected areas.

Secondary Concern

Secondary Concern:

Deep Slabs

Probability:

Moderate

Secondary Concern Comments:

There is lots of buried graupel in the snowpack and it varies quite a bit from place to place. Sometimes it is a little punchy and suspect. Watch for graupel pooling off steep slopes. It also seems worse in thin snowpack areas where there may be a little faceting involved. But on most slopes it does not seem to be a problem and is not reactive.

Elevation:

9800'

Aspect:

Northwest

Slope Angle:

snow_profile_location:

United States

40° 33' 15.9804" N, 111° 40' 12.6804" W

Observed Danger Rating:

Moderate

Forecast Danger Rating:

Moderate

Snow Profile Location

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