Observations from Rubicon Peak and Peak 9,269'.

Location Name: 
Rubicon Peak and Peak 9,269'
Region: 
West Shore Area
Date and time of observation: 
Thu, 01/11/2018 - 11:45
Location Map: 
United States
38° 59' 3.876" N, 120° 7' 46.2504" W
See map: Google Maps
US



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

Three testpits were dug at the below listed locations on Rubicon Peak and Peak 9,269'. These testpits specifically targeted the faceted snow layer(s) that have been the focus of the persistent slab avalanche problem. In all three pits, ECTs scored ECTN. PST at pit 1 scored PST 55/100 end at approx 25 cm below the snow surface. PST at pit 3 scored PST 30/100 end at approx 60 cm below snow surface. In pits 1 & 2, facets were moist to wet. In pit 3 the facets remained dry to moist, similar to moisture level pre Jan 8/9 storm. Significant density changes remain from the firm slab (1F to P hard) to the softer (F+ to 4F- hard) facet layer below.

Pit 1 on Rubicon - N aspect, 8,180', below treeline, HS 80 cm (38.994148, -120.134022)

Pit 2 on Rubicon - NNE aspect 8,710', below treeline (38.991007, -120.133035)

Pit 3 on Peak 9,269' - NNE aspect, 9,080', near treeline, HS 145 cm (38.984410, -120.129514)

Snowcover in this area on N aspects becomes usable above 8,000'. Little to no snow below 7,800'. HS in open areas from 8,100'  to 9,100' ranged from 80 cm to 145 cm. Snow depth increased with elevation.

Snowpack photos: 
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Strong
Precipitation: 
Snow
Air temperature trend: 
Warming
Wind Direction: 
Southwest
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 

Snow showers materialized around 11:30 am on the West Shore Peaks. Snow level was rising at mid day, but was noted around 8,000' - 8,200'.