Observation: Snowbasin Backcountry

Observation Date
02/3/2017
Observer Name
Bill Hunt

Region:

Location Name or Route
Snowbasin backcountry
Weather
Sky
Broken
Precipitation
Light Snowfall
Wind Direction
Southwest
Wind Speed
Strong
Weather Comments
Wind was howling over Mt Ogden out of the SW, building the already large cornices above 9400'. On the ridge to No Name, the wind was very strong out of the East, gusting to estimated 50 to 60mph, not possible to walk at times, and a hazard in its own right. It would be difficult mountaineering conditions above 9000' in wind like that.
Snow Characteristics
New Snow Depth
4"
New Snow Density
Medium
Snow Surface Conditions
Powder
Wind Crust
Melt-Freeze Crust
Damp
Snow Characteristics Comments
A mixed bag of conditions, wind hammered on the ridges, with decent soft snow in the shaded trees, 8800 to 7000 being the best. Rollerballing became evident at 6900', even on a NE aspect in the trees, 11AM. Getting forced over to a SE exposure on the exit, the snow became heavier, 4" of grabby glop on old crust, but still turnable on lower angle slopes. The tight trees took on a new level of hazard in these conditions, forcing slower speeds. Around 6500' the snow really got sticky, that gluelike wet snow reminiscent of warm spring skiing. Exited at 6350'.
Red Flags
Red Flags
Wind Loading
Cracking
Rapid Warming
Red Flags Comments
I did not get above 9000' today. Variable winds had loaded the east, north, and particularly the west aspects from 9000' to 8000'. Lots of cracking, 4 to 5" wind slab triggered on many test slopes.
Avalanche Problem #1
Type
Wind Slab
Trend
Same
Problem #1 Comments
Serious winds above around 8800'. Some styrofoam drifts noted; hard slab could be an unpredictable possibility above 9000'. Softer wind slab below 8800' was fairly predictable today; if the forecasted 5 to 9" occurs, wind slabs could be bigger tomorrow.
Avalanche Problem #2
Type
Loose Wet Snow
Trend
Same
Problem #2 Comments
This looks like a warm storm, for our elevations. A high rain line, and wetter snow could cause some wet slide issues on the south aspects, and below 7000' on all aspects.
Comments
Cornices growing with the wind, this one faces NE at 8950'.
4" wind slab on NE aspect, 8900', was reactive to cuts.
4 to 5" deep wind slab, 8500' W aspect, 35' wide was the largest result, in a half mile of cuts along ridges. Other pockets were 5 to 10 feet wide.
Cracking at 8400', W aspect, cutting near the top of a ridge.
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate
Snow Profile Coordinates