Variable Conditions on Castle Peak

Location Name: 
Castle Peak
Region: 
Donner Summit Area
Date and time of observation: 
Sun, 01/15/2017 - 14:00
Location Map: 
United States
39° 21' 55.6524" N, 120° 21' 28.0008" W
See map: Google Maps
US


Red Flags: 
Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

Variable surface conditions existed at Castle Peak today. On exposed near and above treeline slopes and some exposed below treeline slopes, wind scoured surfaces and firm wind packed surfaces existed. In some areas near the ridgelines, winds had scoured the snow surface all the back to a rain crust. In areas where hard wind slabs existed and on wind loaded test slopes snowpit tests and observations showed a consolidated snowpack with good bonding between and within the layers. Ski cuts on wind loaded test slopes did not produce any signs of instability. Above test slopes where cornices existed, ski kicks could still release cornice pieces but those cornices falling onto the test slopes did not produce any signs of instability. In sheltered non-wind affected areas, soft cold snow still exists on the northerly aspects with surface hoar forming on the surface in open areas. Some of this surface hoar measured up to 20mm in size. The sun exposed slopes held either wet snow or thin breakable crusts. 

Photos 1 and 2: 10 to 20mm surface hoar in a meadow at ~7900 ft.

Photo 3: Wind scoured E facing slopes along Andesite Ridge

Photo 4: Exposed ice crusts along the Castle Peak ridgeline between 8000 and 9000 ft. Lots of exposed ice near the summit. 

Photo 5: Settlement cracks around trees

Snowpack photos: 
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
Clear
Air temperature: 
Above Freezing
Wind Speed: 
Calm
Precipitation: 
Air temperature trend: 
Warming
Wind Direction: 
Accumulation rate: 
More detailed information about the weather: 

warm, sunny calm weather above 7800 ft. all day. Below 7800 ft. the cloud deck hovered between 7400 ft. in the morning and 7800 ft. in the afternoon. An inversion kept the weather cool and cloudy below this elevation. 

Photo 6: Inversion layer at about 7400-7800 ft.