Northwest Avalanche Center

Observation: Public

All Observations

Observation Details

Name:
Brandon Sheely
Observation Date:
January 6, 2023
Submitted:
January 6, 2023
Zone or Region:
East North
Activity:
Skiing/Snowboarding
Location:
5 miles East of Twisp, WA, near the lower two miles of the Elbow Coulee Road.

Signs of Unstable Snow

None reported

Observations

Having a skiable front country snowpack in the Methow Valley this season, it seemed worthwhile to do a report today after seeing considerable deterioration between layers while uptracking. Given, we have 1000k foot runs this year with nearly 100 cm of snowpack on them, some at 45 and 50 degrees along with a substantial widespread rain crust and wind event (in places) profiled within the upper 1/3 of the snowpack where folks on skis sleds, and snowshoes, again, it seemed worthwhile to submit a report here.
The current outlook calls for daily warming at or just above freezing for the next few days which should allow these various layers the opportunity to consolidate, the most important consolidation necessary exists below the existing rain crust, which is found, depending on terrain and aspect, 4" to 7" and seems to include no rounded wind loading granules, at least within the Elbow Coulee drainage, above the considerable rain crust formed in late Dec. Importantly, where that rain crust did not form as thick as it is on South, SE and SW, and East slopes, which is nearly a half inch and capable of supporting a descending skier (personal observation only), it was not capable of supporting an ascending skier always and would collapse an area of around 6' diameter when it did fail. Importantly, what is below that rain crust does include wind event granules of varied depths, which would propagate, under that rain crust the last few days, but not with as much ease as it did today in the afternoon of 1/6. I'll post the video taken of today's pit and an image of that pit post-failure and a pole dug pit which the upper layer failed at after loading it with two four-inch pole baskets to a depth of 5".
It's assumable this week's warming trend will settle this snowpack if it can penetrate that rain crust, otherwise, there will be 4-7 inches of snowpack, plus whatever we get in the next cycles; however, if the rain crust is not penetrated or deteriorated the existing unconsolidated previous snow will remain as various failable layers that are there, and deep enough in this front country snowpack to release as possible D2 and R3, again, assumably.
There were a few, post-rain-crust-event, natural release avalanches of D4 and D3, Catagory R3, which did cover the Elbow Coulee Road and appeared to fail on the Late November, Early December snow layers at the bottom of the snowpack. Those were on both West and East facing slopes eliminating the possibility that they were wind slab related.

In the photos section I'll include some other pits dug in the last few days.

I'll (hopefully) embed a Youtube video here of the pit dug today, 1/6. 🤞. If it doesn't pop up you could follow the link...
https://youtu.be/gMaox5ocaqE

Media

A quick check that failed, today 1/6 at 3 pm, running on top of the rain crust with a slope angle of 40 degrees, after two 4" pole baskets penetrated to around five inches, as seeable in the upper left of the block.
Shovel dug pit failing/running on various layers found below the rain crust, 1/6 at 3 pm.
Slope angle on the looker's right side of the shovel-dug pit, 1/6 3 pm
Slope angle on the looker's left side of the shovel-dug pit, 1/6 3 pm
Profile of snow at 2,500 feet on the mid-slope of a South aspect, slope angle 35 degrees on 1/4 this block did fail below the rain crust with 1/3 my weight pressing down on the block with the shovel scoop.
Rain crust from the mid-slope 2,500 ft pit
Shoveled out snow block near the top of the same slope on the same day, same South aspect, slope here is 25 degrees Notice the bottom of the block in this pic. The entire block will fail and run on the faceted crystals on the very bottom of the snowpack after I apply my skier's weight plus with a hop.
Here, after hopping on the block with skis, you can see the entire block has moved downslope by referencing the last picture, taken before placing pressure above the block.
The rain crust is taken from the dark line in the middle of the snowpack. Noticeably, this upper slope snowpack is shallower, closer to 45 cm, assumably, the result of wind scour
The hill beyond the first ridge in the photo view angling down from right to left is the location of where the two pits dug on 1/4 were located. The skiing there was on fast cold power on top of the rain crust and wonderful until a layer of crust formed the afternoon of 1/5. When the rain crust did fail while skiing that slope it would do so only in a six-foot, roughly, diameter and the now below the rain crust would fail as well but was quickly stopped as running snow would become entrapped under the thick rain crust and upslope against the existing snowpack held under that rain crust. If that rain crust deteriorates from water, warmth, or cold over time, that underlying snowpack will need to reform also in order to provide snowpack stability, assumably.
WordPress Lightbox