Tumalo tour

Red Flags:
Wind

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Updated:
Wednesday, Mar 22, 2017 12:43 PM
Observer(s):
Aaron Hartz
Position:
Pro Ob
Location:
Three Sisters Area (44.004631, -121.642685)
Ob Date/Time:
Wed, Mar 22, 2017 - 12:11 PM
Report Type:
Snow Conditions
Mode of Travel:
Ski or Snowboard

Written Report:
I toured up the west side of Tumalo and found a 7cm (3") layer of new storm snow. It was just enough to make a nice reset of the surface. The wind was alternating from calm to light out of the SW in the trees. Further up in elevation as the trees become more sparse, the wind increased and was transporting snow. moving up toward the summit, the surface changed from fresh snow, to scoured, to pockets of wind drifted snow.
On the summit the was moderate and alternating from the SW to W. Wind transported snow was blowing into the east facing bowl and off to the north flank. There was fresh wind slab forming at the edge of the bowl. I stepped up to the edge of the bowl in a spot where the cornice is minimal. I got cracks coming off my skis and triggered a small wind slab with a 20cm (8") crown. I like to use the top of the Tumalo bowl as an indicator of what might be happening at at other areas near and above treeline.
The visibility in the bowl was poor to nonexistent so I opted to ski off the north side. On the north and northwest side below the summit, there were pockets of wind slab, but it was not widespread. Some of the wind slab pockets were cracking and sliding down as I skied through them.
Aside from wind slabs, I observed no other signs of unstable snow.

Ski quality in the west facing trees was great. The old snow is supportable and the small amount of new snow made skiing very enjoyable.

The avalanche problems I saw on my tour were cornices and wind slab. Even with just a few inches of new snow, the wind slabs can be 4-5 times deeper and form a significant problem. Watch for new wind slabs forming on lee and crossloaded slopes! Cornices will be hanging out at ridge tops until they fall down. Don't be on top of or under them when they do. The wet loose problem is gone for now, but it could come back with warm day time temps and rain below treeline later this week.


More snow and weather information:
Time: 09:00 Elevation: 6440ft Location: West side of Tumalo
Aspect: WSW Sky: Overcast
Precip: None Air Temp: -6C (21F)
Wind: Calm and Light - SW
Height of new snow: 7cm (3")
Height of snow: 285cm
Boot/Ski Pen: 35cm/5cm


Time: 10:00 Elevation: 7700ft Location: Tumalo Summit
Sky: Obscured
Precip: None Air Temp: -6.5C (20F)
Wind: Moderate - SW to W
Moderate Blowing snow to the North through East


Multimedia

Caption: Fresh wind slab at the top of the Tumalo bowl.