Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
March 24, 2023
Submitted:
March 24, 2023
Observer:
NWAC Forecaster - Katie Warren
Zone or Region:
East Central
Location:
Mission Ridge (4600ft-6400ft; Primarily N and E aspects)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
None Experienced

Media/Attachments

A small wind slab pocket released in this confined terrain feature as a skier descended.
Cracking on a small wind loaded test slope.
Even at lower elevations in heavily treed areas, winds had drifted snow around and filled in old skin tracks.
A quick, but intense graupel shower quickly covered my crystal card.
A cold, clear night grew another crop of surface hoar that is preserved in areas sheltered from the wind.
Snowprofile at 6000ft on a north aspect showed a layered, winter snowpack.
Small surface hoar crystals can be found in the most recent storm interface, down 18cm in a snow profile. This interface failed easily in tilt tests.
Old, rounded surface hoar buried on January 4th can still be found down 100cm in this area.

Advanced Information

Weather Summary

Cloud Cover:
Partly Cloudy
Wind:
Moderate , W
New/Recent Snowfall:
Just a trace of snow overnight.

It was a cold day for the end of March with moderate gusty winds. The previous wind effect was widespread, and there isn't much snow left for transport, with many areas scoured down to crusts or holding wind-packed snow. We did get a few short but intense graupel showers throughout the day.

D1 wind slab; A small, shallow pocket pulled out while skiing a confined feature without much propagation.

Snowpack Observations

The snowpack in the Wenatchee Mountains is deep compared to an average season, and consistent coverage exists down to the trailhead at 4600ft. However, steep southern slopes are beginning to show bare dirt in some locations.

Conditions were variable throughout the terrain we traveled and aspect dependent. Northern, sheltered locations held soft snow down to around 5000ft, while southern slopes have a breakable crust on the surface. At upper elevations, wind-affected surfaces are widespread, with drifts up to 10 inches deep and scoured windward slopes.

A snow profile at 6000ft on a northern aspect showed a cold, layered winter snowpack. The most recent storm interface from 3/20-3/21 is weak, with a mix of small surface hoar and precipitation particles. This interface is down 18cm and failed easily in tilt tests but produced no results on test slopes. I found what I believe to be the Valentine's interface down about 50cm. In this location, it presented as slightly weaker (4F+) snow with no melt-freeze crust. The MLK crust is down around 90cm as a thin ice lense, and below that is the 1/4 surface hoar layer down about 100cm. Stability tests did not produce any results on these deeper layers.

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