Observation: Park City Ridgeline

Observation Date
2/20/2014
Observer Name
Bruce Tremper
Region
Salt Lake » Park City Ridgeline
Location Name or Route
Park City ridge line - USA, No Name, Monitors
Weather
Sky
Broken
Precipitation
Light Snowfall
Wind Direction
Northwest
Wind Speed
Moderate
Weather Comments
Cold, post frontal winds from the northwest and scattered instability shower clouds, clearing in the afternoon.
Snow Characteristics
New Snow Depth
8"
New Snow Density
Low
Snow Surface Conditions
Powder
Snow Characteristics Comments

Nice, light, fluffy powder on a supportable base and even the pre-existing ice crusts on southerly faces were much improved with the new dusting of snow.

Red Flags
Red Flags
Wind Loading
Red Flags Comments
Fewer and fewer red flags as more days pass since the last significant loading.
Avalanche Problem #1
Problem
New Snow
Trend
Decreasing Danger
Problem #1 Comments

The lingering persistent slabs still have a chance to break deep and large. They are now buried much deeper than before the storm, making them more difficult to trigger. It's the classic very low probability but very high consequence situation. In the deeper snowpack areas, the place where people could trigger these monsters are from the thin snowpack areas such as a wind blown ridge or in steep, shallow, rocky sections. I'm still choose to avoid the upper elevations north through east facing slopes, espcially ones with recent wind loading, which I would rate as Considerable

It seems like the slopes below about 9,000' have a fairly stout crust from the rain and warm temperatures, so they are probably a notch lower on the danger scale--probably Moderate.

Avalanche Problem #2
Problem
Persistent Weak Layer
Trend
Decreasing Danger
Problem #2 Comments

Yes, we have 8 inches of light powder and we've had a lot of wind from the west and northwest, which created lots of wind damage in the upper elevations and areas of wind deposited snow. But the wind slabs are mostly soft and not terribly reactive. Resorts report the same thing, soft, relatively manageable wind slabs. These will settle out and be less reactive tomorrow.

Snow Profile
Aspect
Northwest
Elevation
9,500'
Slope Angle
25°
Comments

Here's a quick 2 1/2 minute video of the weekend preview as I narrate the snowpack setup and the wind loading conditions along the ridge top. This is for the deeper snowpack areas at 9,500' and above on northwest through east facing slopes. The shallow snowpack areas will have weaker and potentially more unstable snow.

Video
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable
Coordinates