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.

Tumalo slide activity

Location Name
Tumalo Mountain
Three Sisters Area
Kevin Grove
Email Address
Publish this observation?
I would like this observation to be published on the site
COAC Observer
Date and time of avalanche (best estimate if unknown)
Red Flags
Recent avalanche activity
Recent loading by new snow, wind, or rain
Obvious avalanche path
Avalanche Type
Trigger type
Bed Surface
Storm Snow
Weak Layer
Storm Snow
Crown Height
1 ft
Avalanche Width
Avalanche Length
More detailed information about the weather

 Moderate winds persisted throughout the day with occasional strong gusts.  The air temp was -9C and the snow surface temp was -5C.  Very light snow fell off and on without any noticable accumulation.

More detailed information about the avalanche

 There was some avalanche activity on the east facing Tumalo bowl this morning.  14 inches of new snow overnight and moderate-strong west facing winds loaded the top of the bowl creating some significant cornices and wind slabs, primarily on the lookers left zone.  By the time I arrived at the bowl around 10am there was a notable slide on the lookers left slope (R3/D1) restulting from cornices and wind slab over the top of low density(F) new snow.  There was also a small-medium size sluff in the center zone between the rocks. I dropped down into the lookers right zone and assessed the conditions there, about 30 feet down from the summit zone.  I found a fairly uniform pack consisting of 100cm of total snow depth with 30cm of low density (F) new snow over the top of 18 cm of higher density (1F) snow.  This new snow was sitting on the top of 50cm of rain saturated melt-form snow mostly 1F hardness with two noticable 1.5cm crusts, one right at the new snow/old snow interface at 50cm and another around 30cm from the ground.  Compression tests resulted in moderate, progressive compression failures 12cm down along with hard, resistant planar failures 28cm down.  I did not experience any propogations on extended column tests.  After skiing the far right zone and skinning out, I checked out the area that had slid.  The cornices and wind slab that failed left 1-2 ft crowns and were 1F dense snow slabs sitting on top of fist hard new snow.  The slabs were very reactive wherever they existed and very easy results of hand shears as well as cracking was observed all across the lookers left zone.Heads up out there in wind loaded zones and be safe out there. Kevin