Tumalo tour conditions

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Recent avalanche activity

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Wednesday, Apr 26, 2017 9:54 PM
Aaron Hartz
Pro Ob
Three Sisters Area (44.004403, -121.642084)
Ob Date/Time:
Wed, Apr 26, 2017 - 8:33 PM
Report Type:
Snow Conditions
Mode of Travel:
Ski or Snowboard

Written Report:
On the tour up the WSW side of Tumalo, I found about 6-8cm of wet/heavy snow over a melt freeze crust. Below that were combinations of old snow and melt freeze crusts (see below for snowpack test results).

On the Tumalo summit, the wind was moderate and shifting from SW-W-NW. Snow was blowing over the summit toward the easterly facing bowl. The visibility was too poor to determine where the cornices were on the top of the bowl so I did not approach the rollover into the bowl. Instead I went down the ridge on the north side of the bowl. I could see some avalanche debris in the bowl below the summit. The visibility was too poor to see a crown. I stepped to the edge of the ridge and easily triggered a wind slab that propagated 30 meters wide. The crown was about 15-20cm thick.

My chief concern for today was windslab avalanches. Watch for lingering windslabs on lee slopes over the next few days. Also watch for storm slabs on steep and unsupported terrain. Keep watching out for cornices!

This will be my last official post for the season. Thank you to everybody who posted on the obs page this year. A big thanks to MOUNTAIN SUPPLY and OREGON SKI GUIDES for supporting COAA obs posts and weekly summaries! I'm looking forward to a great spring season on the high peaks. See ya next year!

More snow and weather information:
Time: 11:30 Elevation: 6400ft Location: WSW flank of Tumalo
Sky: Overcast Aspect: WSW
Precip: snowing; 1cm/hr Temp: -1C (30F)
Wind: Light - W
Height of snow: over 3 meters
Boot/ski pen: 50cm/15cm
Shovel tilt test: moderate down 20cm on a density change
CTM PC down 20cm
CTH RP down 30cm on a density change
CTH PC down 40cm in the old melt forms