The last avalanche forecast for the 2023-2024 season will post on April 21st. Thank you to all who contributed to the avalanche center this season through observations, volunteer time, and/or financial contributions.

Transitioning Snow in Johnson Canyon

Location Name: Johnson Canyon Region: Donner Summit Area Observation Date & Time: Thursday, April 20, 2023 - 11:00
Location: 39.344350, -120.293931 See map: CalTopo	Is this an Avalanche Observation?: No Conditions Alerts: Rapid or Prolonged Warming Rapid or Prolonged Warming›Rollerballs / Pinwheels Rapid or Prolonged Warming›Strong Sunshine Rapid or Prolonged Warming›Warm Temperatures Terrain Alerts: Terrain Matches the Advisory

Observation made by: Forecaster

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Observation

Description of Snow, Weather, and Avalanche Conditions:

Today's warmer weather and sunny skies turned the recent storm snow into wet surface snow by 11 am on sunny slopes. Ski cuts on steep sunny slopes caused the wet snow to sluff off the old melt-freeze crusts and produced small rollerballs and pinwheels by this time.

This recent snow has not been through enough melt-freeze cycles to become "corn" yet. It still feels sticky and slow underfoot. Shady spots and true north aspects still held cold soft snow. The storm snow depth has settled to 2-4 inches of snow on top of the previous melt-freeze layer.

The recent storm snow sitting on the previous melt-freeze crust. The storm snow has not fully transitioned from cold snow to corn snow.

Ski cuts triggered small sluffs of wet snow on steep sunny slopes at 10:30 am.

Shady or true north facing slopes still held cold soft snow.

Sunny areas had a melt freeze crust on top of soft snow on top of a much thicker melt-freeze layer.

Terrain Details

Terrain: aspects:

Weather Details

Elevation of Observation:

6000-7000 ft.

7000 - 8000 ft.

Blowing Snow:

None

Wind Speed:

Calm

Sky Cover:

Clear

Air temperature:

Above Freezing

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Transitioning Snow in Johnson Canyon

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Transitioning Snow in Johnson Canyon

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