Observation Date
3/10/2017
Observer Name
Derek DeBruin
Region
Ogden
Location Name or Route
Ben Lomond, South Face & Cutler Ridge
Weather
Sky
Overcast
Wind Direction
Northwest
Wind Speed
Light
Weather Comments
Weather was warm for today's up-and-over tour; just above freezing at the trailhead a bit before 0600. Sky was overcast much of the tour (finished around 1230) with the sun hidden behind a gauzy smear of mid to high altitude stratus. The clouds were light enough at times to feel the solar radiation, but thick enough at others to almost obscure the sun completely. Winds were light, generally out of the northwest, only reaching moderate at the saddle above Cutler Ridge with the occasional gust on the summit.
Snow Characteristics
Snow Surface Conditions
Wind Crust
Melt-Freeze Crust
Damp
Snow Characteristics Comments
Given the warm temperatures and the cloudy sky overnight, I was surprised to find a "soft freeze" on the snow surface on much of the mountain as we toured up Cutler Ridge. There was a barely supportable or not-quite-supportable frozen crust on the snow surface on pretty much every aspect and elevation.
The sun has clearly been doing some work on the surface snow. The lower elevations were crusty (and I'm sure damp by later in the day). The north facing mid elevations still had snow that I'd call "rideable," but any other more positive moniker would be quite generous. The sastrugi on the summit cone has been melted considerably, leaving a significantly more even surface. The sun effects also resulted in an icy crust as we ascended this morning from the saddle, making the skinning challenging and a bit precarious, even with ski crampons. The splitboarder in our party elected to boot much of it.
We spent some time waiting on the summit for the snow to soften. Our descent of the south face around 1100 featured glazed wind-affected snow for the upper 500 feet or so, about 1000 feet of okay corn, and the remaining 2500+ feet was grippy, damp mashed potatoes with ski pen to just below the ankle on aggressive turns, just waiting to catch edges for those anxious to get some speed and really link turns.
Red Flags
Red Flags
Rapid Warming
Red Flags Comments
Today's red flag was definitely the warm temps and soft snow. We started early to mitigate the hazard but still rode down the south face near plenty of debris from yesterday's natural wet slides. I'd expect similar issues as the weather stays warm and the face continues to shed.
Avalanche Problem #1
Problem
Wet Snow
Trend
Same
Problem #1 Comments
More of the same tomorrow--loose wet in the afternoon, based on temperature and saturation as dictated by aspect, elevation, and cloud cover. Rollerballs, point releases, and opportunities for bigger slides as well.
Comments
1. An overview of where we saw yesterday's (2017-03-09) avalanches on the south face of Ben Lomond, in the size 1-2 range. It didn't look like anything had run the whole gully yet, but there were numerous debris piles from the side chutes and in the central gully.
2. A closer shot of some of the wet slide debris.
3. A shot of the south side (north facing aspects) of the N. Ogden Divide as we drove past on the shuttle. Things are already starting to get bare.
4. John Fisher about to make his first turn on the south face, just after dropping the summit.
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate
