Observations from Ralston area

Location Name: 
Cup Lake Peak
Region: 
Echo Summit Area
Date and time of observation: 
Wed, 02/17/2010 - 10:00
Location Map: 
United States
38° 49' 46.362" N, 120° 5' 29.9004" W
See map: Google Maps
US


Red Flags: 
Rapid warming
Observation made by: Professional Observer
Snowpit Observations
More detailed information about the snowpack: 

Photo 1: Small piece of looker's L cornice broke naturally shortly after taking this photo (~9:15am) and deposited about 200lbs of snow onto slope below without further activity. No additional cornice drops were observed. Hard to see in photo, but roller balls under rocks are from previous warming.

 

Photo 2: Free water on snow surface at ~9000ft SE exposure at 10am. Top 5cm of snowpack was undergoing wet metamorphism, bonding well to pencil hard snow below. No free water pooling on pencil layer as of 11am - free water only observed in upper 1cm.

 

Photo 3: Surface hoar observed to Cup Lake Peak summit at 9150ft. Not really a future layering concern (already loosing to heat), but a sign of a good freeze last night. SH grains varied from 2mm to 7mm, and increased in size with elevation.

 

N aspects overlooking Upper Echo Lake at 9150ft and over Cup Lake at 8800ft had 5-10cm of dry snow bonding well to snow underneath.

 

Lower elevation trees (to 7600ft in this area) did not benefit from a good freeze last night, but above trees on SE apsects the snow below 5cm remained supportive and previous tracks remained in frozen state into my departure just before 11am.

 

Upon my descent, though I was able to create wet sluffs on steep SE aspects, very little snow became entrained.

Snowpack photos: 
Any other comments about the observation or links to outside pages that have more info on the observation: 

 

Weather Observations
Blowing Snow: 
Cloud Cover: 
Clear
Air temperature: 
Above Freezing
Wind Speed: 
Precipitation: 
Air temperature trend: 
Warming
Wind Direction: 
Accumulation rate: 
More detailed information about the weather: 

Early warming (shortly after 7am) promoted moderate (damaged a car, undrivable) rock fall onto HWY 50 on E aspect towards the top of Echo Summit.

 

By 10am at 8800ft, observed air temp in the shade +4.5c and in the sun +10c.