Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
January 5, 2023
Submitted:
January 5, 2023
Observer:
NWAC Forecaster - Andy Harrington
Zone or Region:
Snoqualmie Pass
Location:
Snow Lake Divide

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
None Experienced
Collapsing? 
None Experienced

Media/Attachments

Textured surfaces on a "fat" wind-loaded convex feature.
Hard to see, but there were wind ripples across Snow Lake. It appeared that some areas were down to an icy surface.
Even down in the trees, the signs of recent windy weather and lack of significant new snow were quite evident.

Advanced Information

Weather Summary

New/Recent Snowfall:
No new snow observed

Today was summarized by mostly high clouds that lowered at times to limit visibility, a few very light flurries, and of course, windy conditions in exposed areas. Although less windy than I anticipated, it was still quite gusty up on Snow Lake Divide proper. Temperatures have moderated significantly and you felt it when you were out of the wind.

No new avalanches were observed. Plenty of old debris from the past week is visible around the valley. We maybe saw some fresher debris higher up on Chair Peak but lost visibility and it was a ways away - so unconfirmed.

Snowpack Observations

Variable surfaces is a term that probably helps to sum up our travels today to Snow Lake Divide and back. We encountered firm and icy, wind-press, breakable crust, stiff Wind Slab, sastrugi, settled powder, and probably a few others that fall somewhere within the spectrum of refrozen ski and snowshoe tracks. All that said, travel conditions were manageable with the southerly exposed fan of Chair Peak providing some of the more challenging and slippery pockets on the ascent (along with the worse skiing on the descent). This slope is also where we found the New Year's Day sun crust was still on or near the surface in untouched areas. The depth of the Christmas Crust is incredibly variable at this point - in some areas we found it 55cm deep, while in others it was on the surface where the snow had been stripped.

We didn't find any reactive Wind Slabs during our travels but were able to get some very isolated cracking when jumping on test slopes. We saw plenty of evidence of the wind, however. Tree debris littered the skin track down low while textured surfaces, wind-loaded pockets that looked fat, and firm wind-pressed snow were abundant throughout the day in wind-exposed areas. We did not observe or make it to the above treeline band due to visibility, so there are still some question marks in that area and the upper NTL as to how reactive slabs may be. Guaranteed there is wind-effect up there, though.

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