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Observation: East Bowl

Observation Date
3/31/2024
Observer Name
Gagne/Costa
Region
Salt Lake » Big Cottonwood Canyon » Silver Fork » East Bowl
Location Name or Route
East Bowl of Silver Fork -> Microwave
Weather
Sky
Obscured
Precipitation
Moderate Snowfall
Wind Direction
South
Wind Speed
Strong
Weather Comments
Sky was everything from obscured to overcast to brief breaks of sun. It must be spring. Sustained winds from the south along exposed ridges that drifted snow well off of ridgelines. A burst of heavy, S3 snowfall late morning with 5-10 cms of new snow. Active wind-drifting throughout the day; "cornice development in realtime" - Russ Costa.
Snow Characteristics
New Snow Depth
9"
New Snow Density
Medium
Snow Surface Conditions
Powder
Wind Crust
Melt-Freeze Crust
Damp
Snow Characteristics Comments
Difficult to measure new snow amounts from overnight given how much wind-drifting. Widespread wind-affected snow and a crust on south aspects below 9,000'.
Out of wind-affected terrain, the new snow on northerly aspects skied great.
Red Flags
Red Flags
Recent Avalanches
Heavy Snowfall
Wind Loading
Cracking
Avalanche Problem #1
Problem
Wind Drifted Snow
Trend
Decreasing Danger
Problem #1 Comments
Widespread wind-drifting both along and well-down off of ridgelines. Drifts were up to 30 cms thick. As wind drifts settle out and with lower wind speeds forecast overnight into Monday, the trend is decreasing.
Comments
Wind-drifting was the player today. Sustained winds (there was never really a break from them even for a moment) from the south created fresh cornices and wind-loaded slopes on many different aspects. Cornices grew so quickly that they would collapse quickly. These were small, but an indication of the rapid wind-loading, with some small natural avalanches from cornice falls along north-facing East Bowl Pass.
Our route today was East Bowl from Alta, with an exit up Grizzly Gulch to the Microwave. We triggered an avalanche on west-facing slope below the microwave and is submitted in a separate avalanche occurrence. This was on a cross-loaded terrain feature and the avalanche occurred on a steep rollover 10m below us.
Wind-drifted avalanches weren't large today, mostly class 1, but they could have been consequential if you were pushed into trees or over cliff bands.
Photos:
- Corniced ridgeline
- Downsloping winds - notice the wind-drifting below the ski tracks!
- Two natural avalanches on a cross-loaded slope above Michigan City.
- The numerous small natural cornice falls we noticed. These were small but indicated the rapid wind-loading that was occurring.
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
None
Coordinates