Observation: Silver Fork

Observation Date
4/18/2013
Region
Salt Lake
Location Name or Route
Alta to BCC, out Silverfork
Weather
Sky
Clear
Wind Direction
Northwest
Wind Speed
Moderate
Weather Comments
Temperatures once again unseasonably cold in the morning and still a bit below average in the pm. Winds in the morning were out of the ENE and NE. Significant plumes were visible off of many of the high peaks. The winds appreared to veer out more out of the NW in the pm; and they still maintained Moderate Category speeds. Transport and or wind blown snow continued through the afternoon.
Snow Characteristics
New Snow Depth
1"
New Snow Density
Low
Snow Surface Conditions
Powder
Dense Loose
Wind Crust
Melt-Freeze Crust
Damp
Snow Characteristics Comments

Another skiff to an inch overnight, and there appeared to be 2 to 3 inches that fell from 1600 to 1800 on the 17th/Wednesday. Overall the snow surface was significantly more dense, stiff and settled out than over the past 72 hours. The new snow appeared to settle out at least 50 to 30%, depending on the aspect and elevation. The best snow can still be found in the more wind sheltered areas on NNW, N and NNE aspects with slope angles greater than 30 degrees. And, these conditions may be actually available as low as 8000 feet, due to the cold temps. The wind definitely played a major part in altering the snow surface from 1400 on Wednesday through Thursday. Much of the upper elevation, northerly, exposed terrain was scoured, sculpted, and or wind rippled. In the areas just off the rideglines and down at least 300 feet on the Northerly aspects the snow was definitely wind thickened. Crusts (m/f) were observed on E, SE and S by 1500 in the upper alpine. All slopes except steeper North got damp at one point or another today.

Red Flags
Red Flags
Recent Avalanches
Wind Loading
Rapid Warming
Red Flags Comments
See Mark Whites report with regard to the Wet activity. In general it appeared that the early morning unseasonable lows kept the activity down to a minium on E and S. There were two small rider triggered slides in the lower South facing gullys off of Toledo and Flag. As I was down by 1500 hours, I did not observe any naturals similar to the activity observed in Cardiff Fork.
Avalanche Problem #1
Problem
Wet Snow
Trend
Decreasing Danger
Problem #1 Comments

Thursdays activity may have played itself out on the SW and W aspects; yet the due S and E aspects may still have a bit of avalanche life left in them on Friday if he sun and temperatures are out in force.

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

Isolated pockets of wind slabs/deposits may still be lingering on Friday. Of note: the unusual forecasted SE winds may help develop/build new drifts and pillows of wind slab on NW and N aspects.