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Observation: 10420

Observation Date
1/4/2020
Observer Name
B
Region
Salt Lake » Big Cottonwood Canyon » 10420
Location Name or Route
10420 SSE
Weather
Sky
Scattered
Wind Direction
Southwest
Wind Speed
Moderate
Weather Comments
Mild temperatures with Light to Moderate Winds in the am, and then veering more Westerly by mid afternoon. Transport and or Wind Blown Light at Mid elevations, and possibly Moderate to Intense in the Upper elevations.
Snow Characteristics
Snow Surface Conditions
Dense Loose
Melt-Freeze Crust
Snow Characteristics Comments
Only a very thin M/F layer from Friday's solar, and afternoon cloud cover appeared to help keep even the southerly aspects cold and dry on Saturday. Good riding on dense settled/creamy powder.
Red Flags
Red Flags
Recent Avalanches
Wind Loading
Cracking
Collapsing
Poor Snowpack Structure
Red Flags Comments
Cracking observed on Wind Loaded NE aspects. Collapsiing observed due to Poor Snowpack Structure in Snow Pit Tests. Wind Loading continuing even at Mid Elevations. At least five more avalanches on Southerly facing aspects with buried PWL's as weak layers definitely accountable for two of them; and there have now been at least 7 avalanches on ESE through SE since Thursday.
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Increasing Danger
Problem #1 Comments
As previously reported four days ago, there is a PWL issue on ESE through SE. This P-Slab problem is now buried even deeper due to the persistent NW-erly winds that have been active for almost 4 days now. These NW-erly loading winds only abated for a brief period of SW today, and they are now veering more W to WNW again this evening. This P-Slab problem has been reported and identified by observations of at least 7 remote and natural avalanches since Thursday. Today in Snow Pits on a SSE aspect at 9200 feet in the 10420 area Poor Structure was observed with .5 mm facets yielding CTM SC Scores. In this location the buried PWL was only 17 cm down, and they were just above a thin M/F crust. All steep sustained ESE-SE may be suspect. And, with the recent observations of multiple avalanches on SW, this P-Slab problem may be on S and SW aspects as well.
Avalanche Problem #2
Problem
Wind Drifted Snow
Trend
Increasing Danger
Problem #2 Comments
Continued Westerly winds appear to be keeping the Wind Slab Problem active and a concern at least on Upper elevations, and possible on Mid elevations as well.
Today's danger rating trended towards Considerable due to all the activity reported, and if the winds continue to load and transport additional snow, Considerable may be appropriate on all aspects at Upper Elevations, and also on E, S and SW aspects in the upper tiers of the Mid Elevations for Sunday.
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable