Cascade Gulch Avalanche

Today’s observation revealed a massive natural avalanche at the top of Cascade Gulch on a southwest face. Spotting this avalanche from town with the naked eye indicates its magnitude. It is clear evidence that the extreme winds from the days prior have significantly loaded pockets of terrain above treeline. Snow below treeline has settled with debris from trees scattering the forest floor. Surface hoar can be found in shady, protected areas. Near treeline on solar aspects, the top 5 - 7 cm of snow has become very moist. Winds were light, with the occasional moderate gust. You can find wind effects in the alpine in the form of sastrugi, wind buff, ice pellets, and hardpack. I witnessed snow transport on the upper mountain with little to none seen near treeline. 

Observation Location: Old Ski Bowl

• Elevation: 8,000 ft 
• Date: 2023.01.23
• Time: 1300
• Observer: E. Falconer
• Sky Conditions: [Clear (CLR) 
• Current Precipitation: Type - None
• Air Temperature: 37 °F
• Surface Penetration: Ski penetration (PS) = 3 in (7 cm), boot penetration (PF) = 12 in (30 cm)
• Total Snow Depth (HS): 40 in (100 cm)
• 24-hour New Snow Depth (HN24): None
• 24-hour New Snow Water Equivalent (HN24W): None
• Wind Direction: N-NW
• Wind Speed: Light (L), 1-16 mi/hr, twigs in motion | Moderate (M), 17-25 mi/hr, small trees sway |
• Column & Block Tests: None preformed.