11th Annual Utah Snow & Avalanche Workshop Open and Motorized Sessions Oct. 27th.
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Observation Date: 
12/21/2017
Observer Name: 
Greg Gagne with "Gunner" Frey.
Location Name or Route: 
Upper Little Cottonwood Perimeter
Weather
Sky: 
Overcast
Wind Direction: 
Northeast
Wind Speed: 
Moderate
Weather Comments: 
Moderate gusts in the morning out of the N/NE.
Snow Characteristics
New Snow Depth: 
5"
New Snow Density: 
Low
Snow Surface Conditions: 
Powder
Wind Crust
Snow Characteristics Comments: 

A generous 10-15 cms (4-6") in upper LCC above 9000'.  Some wind transport along upper elevation ridgelines. Some drifts were up to 45 cms (18") but overall not very sensitive and would only crack around your skis. Dug several quick hand pits and could not find any surface hoar underneath the new snow.

Red Flags
Red Flags: 
Poor Snowpack Structure
Avalanche Problem #1
Type: 
Wind Drifted Snow
Trend: 
Decreasing Danger
Problem #1 Comments: 

Overall was not finding widespread wind drifted snow. Instead, was only finding smaller pockets along upper elevation ridgelines, or just below ridges. Was not finding wind drifts down off of ridges. These drifts were mostly shallow, 10-20 cms (4-8"), however some drifts were up to 45 cms (18"). Overall they were not sensitive to ski cuts and at best I could only get them to crack locally around my skis. The only ongoing concern I have with these drifts is that those that are sitting on top of faceted snow may remain sensitive.

Avalanche Problem #2
Type: 
Persistent Weak Layer
Trend: 
Same
Comments: 

Route today was Grizzly -> Patsy Marley -> Wolverine -> Catherines -> Dry Fork -> Supreme area. Was focusing on the following:

- how widespread and sensitive were fresh wind drifts?

- was any surface hoar preserved underneath the new snow?

- could I get sluffs to run in the new low-density snow?

(Phone battery died very early in the morning, so no photos.)

Wind drifted snow is addressed above.

Lots of quick hand pits today as I was interested in if any of the reported surface hoar that had formed earlier this week had been preserved, and I could not identify any. It seems that the strong pre-frontal winds eroded any surface hoar. The faceted snow at the old snow surface is still evident, but the new storm snow is so low-density it does not form a cohesive slab and I could not get any clean shears with  shovel tilt test.

Could only get minor sluffing in the new snow to move, even on steeper (> 35 degrees) slopes.

Generally Low hazard, with continued Moderate hazard in the upper elevations where there is recent wind loading. Winds are forecasted to increase later Friday afternoon and there is plenty of fresh snow available for transport.

Today's Observed Danger Rating: 
Moderate
Tomorrows Estimated Danger Rating: 
Moderate
Snow Profile Coordinates: 

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