Observation Date
3/5/2018
Observer Name
Zimmerman-Wall
Region
Provo » American Fork » Mary Ellen Gulch
Location Name or Route
Mary Ellen Gulch
Weather
Sky
Broken
Precipitation
Light Snowfall
Wind Direction
West
Wind Speed
Light
Weather Comments
Strong winds and OVC skies to start the morning. S1 Snowfall before 9am. Decreasing clouds and wind after 10am. Sun was very strong once the clouds broke, but the wind and cool ambient temps kept any wet activity at bay.
Snow Characteristics
New Snow Depth
12"
New Snow Density
Low
Snow Surface Conditions
Powder
Snow Characteristics Comments
Storm snow had settled to 12" on the southerly aspects of MEG. Northerly facing sported a bit more. But would say that overall HST from Saturday to Monday was around 15" total.
Red Flags
Red Flags
Recent Avalanches
Wind Loading
Poor Snowpack Structure
Red Flags Comments
Observations included handpits, pole probes, and ski cuts. On southerly aspects, there is a 1cm crust buried beneath the storm snow (~30cm) with facets just beneath. Snowmobile triggered P. Slab on NE facing Y Not Buttress at mid elevation. See Avalanche Ob. Winds drifting onto NE facing slopes and cornice formation is prevalent on MEG/MB ridgelines.
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Same
Problem #1 Comments
Poor structure is still the name of the game and since this zone didn't receive the lion's share of snow, the problem is relegated to convex, rocky breakovers on Northerly facing. Slide pictured below in Y Not is indicative of this issue. Crust/facets on southerly slopes don't have a stiff enough slab to be an issue at this time. Expect this could be different in higher elevation terrain of the upper drainage where winds has created deeper drifts.
Avalanche Problem #2
Problem
Cornice
Trend
Same
Problem #2 Comments
Large cornices forming on the ridgeline between MB and MEG above Pagan Basin. With forecasted warming this week, will be giving these a wide berth and limiting exposure beneath.
Comments
Photos:
1. Persistent Slab in mid elevation Y Not of MEG. Approx: 3'x45'100' . (Center of frame)
2. Sled tracks all over steep terrain in Y Not and Outhouse
3. Large cornice formation above Pagan Basin
4. MEG under clearing skies
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Moderate
