Details

• Date: 2011/01/20

• Observer: Brian Lazar
• Organization: Forecast Staff, Colorado Avalanche Information Center

Location

• BC Zone: Front Range
• Area Description: Pumphouse drainage/ Berthoud Pass.

Weather

• Ridgeline Wind Speed: 40+ mph
• Ridgeline Wind Direction: W
• Wind Loading: Intense
• Temperature: 5 F
• Sky Cover: Scattered
• Weather Description: cold, VERY windy

Snowpack

• Snowpack Description: Reactive storm slab, with some weaknesses within the storm snow. This lies over a stiffer (1F-4f+) wind slab, which sits on a large and reactive SH layer buried 60-80 cm down.

Snowpack Obsvervation #1 Persistent Weak Layer: Yes Comments: Storm slab reactive to skier triggering, and there are multiple weaknesses within the storm snow that produce easy shears (Q2). This is a non-persistent weak layer problem, and this avalanche problem should ease over over the next several days. SH buried 60-80 cm down reactive. CTs M-H, but consistent SC or SP (Q1). One RB 5 on NE at TL, SC/Q1, whole block. The SH layer is persistent and will be a problem for the near-term.

Avalanches

	Date	Location/Path	#	Elev	Asp	Type	Trig	SizeR	SizeD
	2011/01/19  †	Berthoud Pass	1	>TL	E	SS	N	R2	D2
Date: 2011/01/19 (Estimated) Observer: Brian Lazar Organization: Forecast Staff, Colorado Avalanche Information Center Area Description: East Face of Russell Peak Landmark: Berthoud Pass Average Slope Angle: 38 ° Maximum Slope Angle: 45 ° Elevation: 12000 ft Sliding Surface: I - New/Old Interface Weak Layer: Unknown Weak Layer Grain Type: Precipitation Particles Average Crown: 20 in Maximum Crown: 30 in Average Width: 200 ft Maximum Width: 300 ft Average Vertical: 200 ft Comments: two avalanche of similiar character in close proximity
	2011/01/20	Berthoud Pass	1	>TL	NE	SS	N	R2	D2
Date: 2011/01/20 Observer: Brian Lazar Organization: Forecast Staff, Colorado Avalanche Information Center Area Description: NE face of No Name Peak, just north of the summit below larger cornice. Landmark: Berthoud Pass Average Slope Angle: 38 ° Elevation: 12200 ft Sliding Surface: I - New/Old Interface Weak Layer: Interface Weak Layer Grain Type: Precipitation Particles Average Crown: 24 in Average Width: 150 ft Average Vertical: 250 ft Comments: No Name
	2011/01/20	Berthoud Pass	1	>TL	E	SS	N	R2	D2
Date: 2011/01/20 Observer: Brian Lazar Organization: Forecast Staff, Colorado Avalanche Information Center Area Description: East facing head wall north of Stanley Peak. Landmark: Berthoud Pass Average Slope Angle: 37 ° Elevation: 12000 ft Sliding Surface: I - New/Old Interface Weak Layer: Interface Weak Layer Grain Type: Precipitation Particles Average Crown: 20 in Average Width: 200 ft Average Vertical: 200 ft Comments: Stanley Headwall
	2011/01/20	Berthoud Pass	1	TL	SE	SS	U	R3	D2
Date: 2011/01/20 Observer: Brian Lazar Organization: Forecast Staff, Colorado Avalanche Information Center Area Description: This could of run at old snow/storm snow interface, or on Sh layer. Too far away to know for sure. Landmark: Berthoud Pass Average Slope Angle: 35 ° Elevation: 11500 ft Sliding Surface: Unknown Weak Layer: Unknown Average Crown: 24 in Maximum Crown: 36 in Average Width: 150 ft Average Vertical: 200 ft Comments: Sam Knob in Current Creek