Observation: American Fork

Observation Date
Observer Name
Provo » American Fork
Location Name or Route
American Fork-Mary Ellen
Wind Direction
Wind Speed
Weather Comments
Clear skies with a few lingering clouds during the tour. Heavier cloud deck moved in around 230PM. Winds were blowing strong from the south-southeast and the air temperature was right around 32°F at the highest elevations (11,000') and in the low 50's °F at the 8,000' weather stations. The winds kept the snow surface cool at higher elevations during the tour.
Snow Characteristics
Snow Surface Conditions
Melt-Freeze Crust
Snow Characteristics Comments
Snow was a mixed bag of very frozen melt-freeze crust on northerly facing high elevation slopes and damp snow surface at lower elevations down to 8,800'. The winds kept the surface from becoming too damp but if you stepped out of your skis on solar aspects you would sink into the snow surface.
Photo of still frozen snow on a northwest facing slope at 10,600'
Avalanche Problem #1
Wet Snow
Problem #1 Comments
Photo of stacked up wet loose debris on steep southwest facing aspects that ran 1200-1600' vertical in American Fork Canyon (photo 1) from a previous day. The snow really needed the heat of the rocks to create enough warming. More planar slopes had roller balls (photo 2) but less wet snow gouging.

Snow Profile
Slope Angle

Today, was a tale of timing. The upper snowpit was dug earlier in the day at a higher elevation site that was more in the wind zone. This pit showed a supportable surface with weak wet grains 6" from the surface. This slope was skied and yielded great skiing from the peak to the drainage bottom.
The below snowpit was dug in a less windy zone later in the day with more sun affect. This second snowpit also showed weak wet grains 6" from the surface, however the surface snow was much weaker and the snow surface may have been supportable skiing, but we were too late and elected to find something else to ski that was more supportable. What is interesting is that both snowpits had percolation columns (page 10 of 13) below the crust which is a sign that the water has established a way to move through the snowpack (think of it like plumbing). The higher elevation snowpit had percolation columns from under the crust to the ground. The lower elevation pit had percolation columns going from under the crust to the dirt layer and those columns in the thicker snowpack had not made it to the ground- This is something to keep an eye out for as water may pool above the dust layer.
For a quick read about water pooling check out Drew's blog from the Thursday April 11 HERE.
Today's Observed Danger Rating
Tomorrows Estimated Danger Rating