Light Accumulation on Andesite Ridge

Location Name: 
Andesite Ridge
Region: 
Donner Summit Area
Date and time of observation: 
Sat, 01/11/2014 - 14:00
Location Map: 
United States
39° 21' 3.3264" N, 120° 21' 59.922" W
See map: Google Maps
US


Red Flags: 
Recent loading by new snow, wind, or rain
Obvious avalanche path
Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

1 to 3 inches of new snow had fallen by 3 pm in the Andesite Ridge area today. On the near and below treeline N-NE aspects this snow fell on old snow surfaces consisting of thin melt-freeze crusts and weak facetted snow. Above treeline it landed on a mix of old scoured snow surfaces and patches of bare ground. With snowfall amounts staying near the low end of forecasted amounts reactive wind slabs did not form in this area on wind loaded slopes. Tests and observations still showed that the old persistent weak layers remain buried, but they have become dormant as the slab above them has disintegrated. The meager snow accumulations did not add enough weight or new slabs to the snowpack to reactivate these old weak layers. Mostly this new snow just made it more difficult to see the rocks and other obstacles still exposed or just barely covered on the slopes.

Photo: A NE facing slope near the top of Andesite Ridge with numerous rocks and other obstacles still exposed.

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: 
Cooling
Wind Direction: 
Southwest
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 

Winds were light below treeline, and moderate to strong above treeline. They seemed to be decreasing by the afternoon. The heaviest snowfall seemed to occur between 11:30 am and 1:30 pm. By 2:30 snowfall had almost stopped.