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Observation: Brighton Perimeter

Observation Date
Observer Name
Salt Lake » Big Cottonwood Canyon » Brighton Perimeter
Location Name or Route
Brighton Perimeter
Moderate Snowfall
Wind Direction
Wind Speed
Weather Comments
Most of the day skies were OVC with a brief period of Broken in the early afternoon. Brighton area received 3 fast inches before 0900 and then only Light Snowfall until 1600. At 1800, it is now snowing S2 at least. Moderate SW winds veered more out of the WNW by 1400. Moderate Wind Blown observed at mid and upper elevations. Temperatures remained mild all day long with 9000 highs remaining around the freezing level.
Snow Characteristics
New Snow Depth
New Snow Density
Snow Surface Conditions
Wind Crust
Snow Characteristics Comments
Despite the seasonally mild temperatures, the all new snow remained cold and dry above 9000, and the new snow bonded well to the old snow surface. Below 9000, the new snow at the old snow interface was damp in it's first inch, with the upper layers dry. Above 9000 feet, there was a sensitive/reactive density break that was easily identified in hand shears. And even though this Storm Slab layer was reactive throughout the entire day, the shallowness of this Storm Slab was inconsequential. As this layer remained reactive even at the end of the day, it may still be an issue early on Saturday.
Fridays elevated daytime highs combined with a lack of overnight refreeze has contributed to damp/moist layers 12 to 18 inches down. As a result of the lack of surface refreezes, there was good riding on a spongy base in the 5 inches of new snow.
12 inch deep, 4 Finger Stubborn Wind Slabs were observed.
Red Flags
Red Flags
Wind Loading
Poor Snowpack Structure
Red Flags Comments
Poor Snowpack Structure confined only to the previously cited lingering Storm Slab sensitivities. These will likely settle out with the warm snowpack and and mild temperatures forecast for Saturday. Yet, they may remain reactive in the early morning hours. No travel today travel on the Upper Ridgelines. Wind Loading was likely in the exposed Alpine with the Gusty/Strong SW-WNW Winds that have been active throughout the storm.
Avalanche Problem #1
Wind Drifted Snow
Problem #1 Comments
See above, and with the forecast calling for a continuation of these kinds of periodically gusty winds, this issue will continue to be a concern.
Avalanche Problem #2
New Snow
Increasing Danger
Problem #2 Comments
See above with regard to Storm Slab possibilities. The storm continues to have periods of heavy PI, and as a result, there may be reactive Storm Slab Layers of concern.
Also of concern are the Large Cornices that are looming, and possibly still developing with the dense new snow and wind.
Danger today appeared to be Moderate with the only real concern potential Wind Slabs. If the forecast verifies and we receive the upper end of the snow and water amounts, avalanches of up to 2 feet may be possible and Danger Rating may escalate to Considerable.
Today's Observed Danger Rating
Tomorrows Estimated Danger Rating