Pinwheels and Wind on Tallac

Location Name: 
Tallac
Region: 
Desolation Wilderness Area (including Emerald Bay)
Date and time of observation: 
Wed, 04/12/2017 - 11:00
Location Map: 
United States
38° 54' 54.378" N, 120° 5' 15.8388" W
See map: Google Maps
US


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

Rain and wind on Tallac up to at least 9000 ft. where the clouds and fog rolled in. On E-SE-S aspects a supportable but soft combination of wet snow and crusts existed. Ski cuts on these aspects did not trigger anything but very small pinwheels (up to 8 inches in diameter) that quickly broke apart. On the N-NE aspects below 8700 ft. about 12 inches of rain-soaked wet snow existed. Ski cuts triggered larger pinwheels (up to 3-4 ft in diameter) and some loose wet sluffs that entrained all of the wet snow. Above 8700 ft, a mix of a thin rain crusts and wind packed snow surfaces existed on these aspects with cold dry snow below the surface.  

Photo: Loose wet sluff on a NE aspect at 7500 ft. 

Video: Pinwheels on a N aspect at 7300 ft. 

Snowpack photos: 
Snowpit videos (tests, etc): 

Pinwheels on a N aspect at 7300 ft. on Tallac

Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Strong
Precipitation: 
Rain
Air temperature trend: 
Cooling
Wind Direction: 
Southwest
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: