Observation: Alta Periphery

Observation Date
3/19/2023
Observer Name
Champion
Region
Salt Lake » Little Cottonwood Canyon » Alta Periphery
Location Name or Route
Alta Periphery
Weather
Sky
Broken
Wind Direction
Southeast
Wind Speed
Moderate
Weather Comments
As the weather moved, sky coverage increased, going from scattered to broken to overcast by the end of the day. Winds were moderate along ridgelines, with noticeable flagging along the highest peaks. The cooler temperatures and winds seemed to keep any wet snow at bay in the terrain we covered.
Snow Characteristics
Snow Surface Conditions
Wind Crust
Melt-Freeze Crust
Snow Characteristics Comments
The snow surface has morphed into a variety of good bed surfaces for the incoming storm. Anything all southerly facing, or true easterly has been heavily impacted by the strong sun over the last few days. Even before the strong sun and warmer temperatures, the lower elevations had received a lot of moisture falling as a rainy snowy mix late last week and are now frozen rather solid. On the shaded aspects, the winds have taken a toll on the snow surface in many areas. Across the board, both solar and non-solar aspects it appears that the snow surface has been weakening over the past few cold clear nights.
Comments
Today, we headed out to check out the snow surface conditions and what the snow looked like moving into this next week of storms. We did not experience any obvious signs of instability, and primarily traveled in high elevation terrain both in and out of the solar zone. Winds continued to transport snow throughout the day, but we did not see any activity within the wind drifted snow.
My primary concern today wasn't the current conditions but will be the snow surfaces leading into this week's snowfall. Almost all aspects and elevations have taken a brutal beating from the rain/snowfall, heavy winds, and intense sun. Solars have a generally firm snow surface, and outside the solars, the winds have left both a smooth wind crust in areas some or created a variety of wind-textured firm surfaces in other areas. Slightly more protected terrain features below ridgelines still held some soft snow, but even the soft snow had a slight skin forming. On top of these firm surfaces, the snow has begun to weaken and facet. I found this in most aspects I traveled today, both solar and non-solar. Going into this week's snow, depending on how the new snow bonds, the freezing levels, and the intensity that the snow falls we could see pretty wide spread sensitivity during and directly following the storm. Directly along ridgelines, where the wind has been hammering the slopes the most, I would be less concerned about the weak snow being well-connected, but out of the wind zone in more protected terrain we noted weak snow in most places.
As well, cornices continue to grow in size. We saw a few along large ridgelines, and continue to grow. With multiple days of heavy snow and high, winds I would guess we see a few more natural cornice drops leading to new snow and wind drifted snow avalanches triggered below.
Photo of flagging along ridglines, wind drifted snow texture, and an old avalanche from the last cycle.
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
None
Coordinates