Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
January 3, 2023
Submitted:
January 3, 2023
Observer:
NWAC Forecaster - Katie Warren
Zone or Region:
East Central
Location:
Icicle Creek (2800-6400ft; primarily N & W aspects)

Signs of Unstable Snow

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

Media/Attachments

A bit of trail maintenance on Icicle Creek Road.
A melt-freeze crust existed at lower elevations, from 2800ft to 5000ft.
Small wet loose avalanches were visible in steep, rocky terrain where the sun had warmed slopes.
On southern aspects a melt freeze crust exists with rimed surface hoar on top.
Above 4500ft we found rimed surface hoar on all aspects.
Wind swept ridges and good views were common once you got above the clouds.
Wind drifted snow in sparsely treed terrain at higher elevations.
Rimed surfaces indicate wind direction, helping to identify potentially wind-loaded terrain.
After a brief break midday, East flow pushed clouds back into the valley around 3:30pm.

Advanced Information

Weather Summary

Wind:
Calm

We were surprised by some light rain at the trailhead and low clouds hung in the valley. As the day progressed, we climbed out of the valley clouds into a calm sunny day above 5000ft. Valley clouds dissipated slightly midday, thickening again by 3:30pm.

Small wet loose avalanches were observed in steep rocky terrain on southern aspects.

Snowpack Observations

At the trailhead located at 2800ft, we found an HS of 70cm, with 15cm over the Christmas Crust. In addition, the snow surface had a breakable 2cm thick melt-freeze crust. This potentially formed from the recent rain, but it was surprising to find this crust so far east of the crest.

The Christmas Crust from 2800ft to 5000ft was very hard and made for challenging and slippery travel conditions. While ski crampons were helpful, I can't say they made the climb easygoing.

Around 4500ft, both the surface crust and the Christmas crust began to break down, making for easier travel. The surface crust on northerly aspects was gone by 5000ft. At all elevations, southern aspects still had a sun crust approximately 2cm thick. We found rimed surface hoar on all aspects. Surface hoar rested over a sun crust on southern aspects, soft snow on sheltered northern aspects, and on top of wind stiffened snow near ridgelines.

We climbed to 6400ft where the HS was 190-200cm with 50cm of snow over the Christmas Crust. While there was evidence of drifting snow near ridgelines and shallow hard wind slabs were present, they were unreactive to ski tests. We could get resistant planer hand shears with moderate force on the Christmas Crust, but the no signs of reactivity when testing steep rolls in the terrain.

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