Tumalo tour conditions

Friday, Mar 31, 2017 6:10 PM
Aaron Hartz
Pro Ob
Three Sisters Area (44.005092, -121.642470)
Ob Date/Time:
Fri, Mar 31, 2017 - 5:11 PM
Report Type:
Snow Conditions
Mode of Travel:
Ski or Snowboard

Written Report:
As I toured up the west side toward the tumalo summit, I could see avalanche debris over on S. Sister below the Lewis glacier headwall. I could also see avalanche debris on the lower part of the high noon face of Brokent top. It was impossible to tell the type of avalanches, trigger, or how big the avalanches actually were. Both locations are of similar aspect and elevation (southerly, high alpine). It is possible they were related to wind wind loading by the recent north wind and new snow.

Touring up the west side of Tumalo - The surface ranged from 20cm of recent storm snow to 30cm of wind drifted snow to wind scoured crust.

On the summit - the wind was moderate out of the north and blowing snow was moving along the summit plateau. Wind was also coming upslope out of the bowl. There are still large cornices lining the Tumalo bowl. The snow surface in the bowl was very wind affected from cross slope and up slope wind coming out of the north. Below the summit on the north side, the snow was scoured to old crust.

Further down the NNW side in the trees the powder was still really good. Surface hoar was present down in the wind protected trees. Pit tests showed the new snow is bonding well and no major weak layers in the upper 75cm of snow.

I skinned back up to the summit. The wind had backed off to light our of the north. I skied off the south side. There were some shallow wind slabs. As I skied over some convex rollers, I got some cracking on the wind slabs from my skis. I could not get slabs to break loose. Skiing back to Dutchman was sticky in sun exposed areas. Powder was still good in the shade.

More snow and weather information:
Time: 12:00 Elevation: 7700ft Location: Tumalo summit
Sky: a few clouds
Precip: None Air Temp: -4C (25F)
Wind: Moderate - north
Blowing snow - moderate; north

Time: 12:30 Elevation: 7700ft Location: Tumalo summit
Aspect: NNW Sky: a few clouds
Precip: None Air Temp: -4C (25F)
Wind: very Light - north
Height of new snow: 19cm (7.5")
Height of snow: 3m+

Shovel Tilt Test - no result
CTH BRK down 25cm below 03/29 rain crust
CTH BRK down 30cm on a density change
CTH BRK down 35cm on a density change
Temperature: -4°C Sky: A few clouds Wind: North @ 17-25 mph
Elevation: 7700 ft