Details

• Date: 2023/03/02

• Observer: Chris Bilbrey
• Organization: Forecaster, CAIC

Location

• BC Zone: Southern San Juan
• Area Description: Parrot Peak

Weather

• Ridgeline Wind Speed: 5-10 mph
• Ridgeline Wind Direction: N
• Wind Loading: Light
• Sky Cover: Clear
• Weather Description: Temperatures warmed nicely under bountiful sunshine. Generally light north wind, but brief periods of gusts into the 20s contributed to blowing snow along ridges.

Snowpack

• Snowpack Description: We traveled on north through east to southwest-facing slopes up to about 11,200 feet. We found 12 to 14 inches of new snow below the treeline. New snow depths inched toward the 16 to 18 inch range at 11,000 feet and above. Unlike the two previous storms, this round of snowfall arrived with much colder air and is lower density. Warmer temperatures helping the storm snow settle kept the loose sluff threat confined to the top couple of inches of snow mostly reactive on steep, shady convexities. The snow surface on sunny slopes showed the effects of the strong March sun becoming moist and sticky by midday. This was more pronounced below 10,000 feet while the snow surface above that elevation on the same aspects was slower to soften. Steep, sunny slopes produced numerous rollerballs but none gained enough mass to entrain additional snow volume. The snow surface on northerly-facing slopes was less affected by todays warmth like their southern counterparts where we traveled. We observed moderate dirty shears below the storm snow on north to east-facing slopes likely influenced by the slabs soft nature. The snow in drifted areas along the ridge felt wind-thickened versus slabby.

Avalanches

• Avalanche Description: Early morning light provided evidence of numerous loose snow avalanches or soft storm slabs on high southerly-facing slopes near Gibbs Peak and along the Knife Ridge between Babcock and Spiller Peaks. They likely ran on March 1, 2023 during a period of heavy precipitation intensity. These were mostly smaller in size, but a few on Gibbs Peak looked to have traveled a long distance down the slope growing large in size.

	Date	Location/Path	#	Elev	Asp	Type	Trig	SizeR	SizeD
	2023/03/01  †		1	<TL	NE	SS	N	R1	D2
Date: 2023/03/01 (Estimated) Observer: Chris Bilbrey Organization: Forecaster, CAIC Area Description: Parrot Peak Elevation: 10400 ft Sliding Surface: S - Within Storm Snow Weak Layer Grain Type: Precipitation Particles Maximum Crown: 12 in Maximum Width: 150 ft Maximum Vertical: 600 ft Comments: Hard to say with certainty if this was a LDa or SSa. Nonetheless, it was a soft slab that failed in the storm snow and likely during heavy PI. The slide traveled a respectable distance down the slope.
	2023/03/01  †		2	>TL	SE	L	N	R1	D1.5
Date: 2023/03/01 (Estimated) Observer: Chris Bilbrey Organization: Forecaster, CAIC Area Description: Gibbs Peak Elevation: 12000 ft Sliding Surface: S - Within Storm Snow Weak Layer Grain Type: Precipitation Particles

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