** IMPORTANT ANNOUNCEMENT **

As of March 30th, COAC has suspended backcountry avalanche advisories and pro observations until further notice.

On March 23rd, Governor Brown of Oregon issued Stay at Home orders for the public regarding the COVID-19 outbreak. The directives are clear in that “to the maximum extent possible, individuals stay at home or in their place of residence.” On March 27th the Deschutes National Forest issued a closure of all developed recreation sites including trailheads and snoparks. COAC is committed to supporting our community, local emergency services, and agency partners and because of this we felt it important to cease operations as we all work together to minimize the impacts and spread of COVID-19.   

This decision was not taken lightly. Aside from the need to maintain congruency with the Governors' orders, there are inherent risks with backcountry activities in alpine environments and it’s important to consider unnecessary exposure to COAC forecasters, first responders, and local medical staff in light of the current situation.

We look forward to getting back into the mountains and providing you all with the tools to recreate safely in the backcountry. Until then we thank you for your continued support and wish all our mountain community the best of health and wellness.

Avalanche on Tumalo Bowl

Location Name
Tumalo Mountain
Region
Three Sisters Area
Name
Jeff Myers
Publish this observation?
I would like this observation to be published on the site
Position
Public
Date and time of avalanche (best estimate if unknown)
Red Flags
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
Obvious avalanche path
Avalanche Type
Dry
Slab
Blowing Snow
Yes
Trigger type
Skier
Wind Speed
Light
Slope
34degrees
Wind Direction
Northeast
Air temperature
Below Freezing
Aspect
Northeast
Air temperature trend
Warming
Elevation
7775ft.
Bed Surface
Storm Snow
Cloud Cover
75% of the sky covered by clouds
Precipitation
Snow
Weak Layer
Other - please provide details in the comment field below
Crown Height
1 ft
Accumulation rate
<1
Avalanche Width
130ft.
Avalanche Length
300ft.
Terrain
Above Treeline
More detailed information about the weather

Light to moderate winds @ approximately 15-20mph, snow fall was very intermittent

More detailed information about the avalanche

Intentionally skier triggered on a convex area between the rock and cornice on the left side of Tumalo bowl.

First attempt (two ski stomps) to trigger the slide sent a shooting crack approximately 30ft into the bowl, Second attempt (two ski stomps)had the entire slope fail.

Weak layer was approximately 10-14in. down and was roughly 1/3in. deep, crystals looked like buried surface hoar. Test Pit showed two failures of CT 1 Q2 @ 10in.

A second weak layer was also present at approximately 20-24in., also a wind slab but with much less energy

Wind slab seemed to be formed from overnight snow blowing in