Green Butte

20191217 - 1500 hrs - Sorenson - Green Butte 

• SKY: Scattered
• PRECIP: None
• BLO-SNOW: No
• AIR TEMP: Above freezing
• SURF PEN: 1.5 in (4 cm)
• HEIGHT OF SNOWPACK: 32 in (80 cm) at 8,800 ft
• HEIGHT OF NEW SNOW: 0
• WIND: Strong southeast 

Notes:  A strong, northwest wind event that started early Friday (12/27) morning has transformed the snowpack near and above treeline on Mount Shasta. Open areas are scoured down to the December 19th ice crust throughout above treeline terrain on Green Butte. Patches of wind packed stastrugi snow remain in more protected areas. No cracking or signs of instability were observed.

A thin wind crust over loose powdery snow 6-10 inches deep all above the Dec 19th rain layer can be found in protected areas below treeline. This snow was quickly transitioning due to warming temperatures. 

The remains of a natural triggered wind slab avalanche was observed in Powder Bowl on a south east aspect at 9,000 feet. Judging by the debris pile the avalanche was D1 to D1.5 in size. The wind has completely stripped the starting zone and only the largest blocks of debris remain (see photo below).