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Observation: Pre-Laurel Peak

Observation Date
2/21/2018
Observer Name
Trenbeath, Forgensi
Region
Moab » Laurel Highway » Pre-Laurel Peak
Location Name or Route
Julie's Backside
Weather
Sky
Obscured
Wind Direction
Southeast
Wind Speed
Moderate
Weather Comments
Blustery day, especially above treeline. Coldest day of the year with overnight temps below 0 at 11,000' 10F at noon.
Snow Characteristics
Snow Surface Conditions
Powder
Dense Loose
Snow Characteristics Comments

6" of nice settled powder from Monday's 10" low density storm. Wind affected above treeline. Finally enough base for turning and riding. 38" in Gold Basin and 26" at the Geyser Pass Trailhead. Dense snow from storms 2-13 through 2-15 is keeping you up above the buried facets and assorted ground obstacles.

Red Flags
Red Flags
Wind Loading
Poor Snowpack Structure
Red Flags Comments
Lots of wind transport going on above treeline with drifting on E,N,W aspects. Crossloading a factor and drifting far downslope. Snowpack structure remains poor with faceting up to 45 cm. Bottom 20 cm are 2mm. No collapsing today for the first time in weeks, ECT's are more stubborn but still reactive at ECTP21 at the ground.
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Same
Problem #1 Comments

Though wind slabs are widespread, PS seems to present the greatest danger with avalanches up to 3' deep still likely on steep NW,N,E facing slopes right around treeline and above. Recent storm (10" @ .5) was not enough of a load to produce natural activity as the snow came in without wind. I think .5 in 12 hours would be enough with strong winds. A few natural PS avalanches occurred one week prior after incremental loading over a period of 5 days with 1.5-2" SWE. We have a classic scenario of adding straws to the camel's back.

Avalanche Problem #2
Problem
Wind Drifted Snow
Problem #2 Comments

Lots of wind transport going on above treeline with drifting on E,N,W aspects. Cross loading a factor and drifting far down slope. Depths varied from 6" to 18". A triggered wind slab has a high likelihood of stepping down and causing a deeper persistent slab avalanche.

Snow Profile
Aspect
Northeast
Elevation
11,000'
Slope Angle
21°
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable
Coordinates