Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
January 28, 2023
Submitted:
January 28, 2023
Observer:
NWAC Forecaster - Andy Harrington
Zone or Region:
Snoqualmie Pass
Location:
Cave Ridge

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
None Experienced

Media/Attachments

An interstorm layer from Friday's snowfall was highlighted with multiple snowpack tests.
Cloudy skies mixed with patches of blue allowed for some views around the zone. You can just make out recent wet loose avalanches on these slopes from Friday's warmup.
Multiple layers of interest still exist in the upper snowpack above the prominent MLK crust. This is the area where you should focus your attention.
Recent rollerballs and small wet loose avalanches from Friday's warmup. The snow surface is now crusty after temperatures have dropped.

Advanced Information

Weather Summary

New/Recent Snowfall:
No new snow observed.

A lot of high and low clouds today but there were some sun breaks and a bit of blue sky here and there. Right at the ridge there were some light winds. When I exited the field around noon it was pretty warm at lower elevations.

No new avalanches observed from today, but plenty of recent avalanches from yesterday's warmup and wet cycle. Rollerballs, pinwheels, and wet loose avalanches were observed on multiple aspects and at multiple elevations

Snowpack Observations

The snowpack took a real beating during yesterday's warmup. A night of cool weather left us with firm and crusty surfaces on Saturday morning, with a few cms over the crust in isolated locations. On slopes that don't see direct sunshine, there was still some well-settled powder in places (that appeared to get warm as well), but many of these slopes also contained a temperature crust capping Friday's 6 inches of new snow.

Friday's snow sat on a melt-freeze crust from earlier this week (1/27 interface) and most snowpack tests highlighted a reactive interstorm layer a few cms above the 1/27. This was failing as easily as CT1 and also showed up in tilt and shear tests. It did not propagate during ECT tests.

Below the 1/27, other layers popped up during small column tests such as the 1/21 and the MLK crust. The 1/21 was found about 25cm below the surface and failed Q1 medium in small column tests, but did not show up during my ECTs.

The MLK is approximately 60cm below the surface and beginning to facet. It repeatedly showed up in small column tests (CT+1 Q1 and shovel shear) but more concerningly, it failed and propagated during a non-standard ECT, Q1. The column width was not a full 90cm during this test. When I repeated the test with the full column width, the layer did not fail and propagate. A bit of a head-scratcher, but something to keep in mind moving forward. I talked to a Pro 1 avalanche class on my exit and they did not have any propagation while demonstrating an ECT test at lower elevations.

Overall, poor ski conditions with breakable crust, firm crust, small pockets of dry snow, and small pockets of manky moist snow.

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