UDOT PLANNED AVALANCHE CLOSURES!!
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Observation: Mary Ellen Gulch

Observation Date
2/6/2025
Observer Name
Zimmerman-Wall/ AIARE PRO 2
Region
Provo » American Fork » Mary Ellen Gulch
Location Name or Route
Sinner's Pass/Mary Ellen Gulch
Weather
Sky
Scattered
Wind Direction
Southwest
Wind Speed
Strong
Weather Comments
Tour was from 1200-330pm. Notable wind transport and gusts in the strong category. Building clouds by 2pm ahead of the front. No notable warming or solar influence.
Snow Characteristics
New Snow Depth
2"
New Snow Density
High
Snow Surface Conditions
Dense Loose
Wind Crust
Melt-Freeze Crust
Snow Characteristics Comments
On north facing aspects, the 2" of graupel from yesterday had been pressed into many terrain features and created a uniform blanket across slopes between 9800-9000'. The underlying surface was spongy, and had some rebound. This indicated that although it was colder overnight into today, the prior snow had seen notable warming effects, even in shaded terrain.
On south and southwest, the wind had eroded a lot of the surface snow back to crust on slopes stepper than 25 degrees. Just below this crust there were small grain facets. And another 8 inches down there was a more developed crust with larger facets beneath. Something to keep in mind later with this new load forecast over the weekend.
Some panels of soft creamy turns could be found in depressions as well. Steep slopes were barely edge-able due to wind damage.
Red Flags
Red Flags
Recent Avalanches
Wind Loading
Cracking
Poor Snowpack Structure
Avalanche Problem #1
Problem
Wind Drifted Snow
Trend
Increasing Danger
Problem #1 Comments
Numerous avalanches could be seen across the drainage. These are noted in a separate avalanche observation.
We were able to count up to four distinct slides (3 wind slabs and 1 cornice fall). The wind slabs appeared to be small, but could have been bigger and the debris was just blown in. Either could have injured a human, particularly in the terrain features they were located with exposure below. These looked 1-2' deep and could have run on the most recent PWL below the storm snow. The cornice had intact chunks that were appliance sized.
Avalanche Problem #2
Problem
Persistent Weak Layer
Trend
Same
Problem #2 Comments
As mentioned above, these wind slabs could have failed on this layer, but we were 1/2 mile away and viewing through a scope.
Comments
On the tour we found interesting things worth sharing:
1. Truck sized overhanging cornice on Pagan Basin ridgeline between Mineral and Mary Ellen
2. Smaller drooping cornice on Miller Hill. Note the new cornice growth on the old cornice.
3. Eroded surface from the windward side of the same ridgeline.
4. Localized drifts that would crack under the weight of a skier up on the ridge.
5. Wind slabs on NE 9600' aspect across the drainage (same as listed in Avalanche Ob)
6. Cornice fall on NE 9800 aspect across drainage (same as listed in Avalanche Ob)
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
None
Coordinates