Details

• Date: 2013/05/29

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

Location

• BC Zone: Front Range
• Area Description: Ptarmigan Point cirque

Weather

• Ridgeline Wind Speed: 10-20 mph
• Ridgeline Wind Direction: NW
• Wind Loading: None
• Temperature: 50 F
• Sky Cover: Scattered
• Depth of Total Snow: 150 cm
• Weather Description: Warm, sunny and calm in the early hours below treeline. By the time we hit the Continental Divide around 10am, moderate northwesterly winds and increasing cloud cover kept things from getting too warm.

Snowpack

• Snowpack Description: The transition to spring is mostly complete except for high-elevation north facing-slopes. In these areas, weak layers at the bottom of the snowpack are rounding rapidly but still have faceted features. Water is percolating through the snowpack but well developed drainage has not yet been established. On all other aspects, the snowapck is wet with well developed drainage. The surface is freezing on clear nights, but the depth of the freeze was only 3 to 5 inches.

Snowpack Obsvervation #1 Comments: The dust layer was apparent on all but north aspects. Once the sun came out these surface turned to corn by 9am. By 11am, it was already wet and time to exit any steep terrain. The snowpack is fully into spring mode with lots of liquid water at the base.

Snowpack Obsvervation #2 Comments: Dust mostly buried still on these slopes. The snowpack is mostly transitioned to spring conditions, but the depth hoar retains faceted features. The mid pack slabs are moist to wet, and are holding water in many place ,as the drainage has not been established. The potential for wet slabs still persists on these slopes.

Avalanches

	Date	Location/Path	#	Elev	Asp	Type	Trig	SizeR	SizeD
	2013/05/29  †	Rocky Mountain National Park	5	>TL	S	WL	N	R2	D1.5
Date: 2013/05/29 (Estimated) Observer: Brian Lazar Organization: Forecast Staff, Colorado Avalanche Information Center Area Description: Notchtop area. Wet loose slides visible in many locations on east and south aspects. Landmark: Rocky Mountain National Park Average Slope Angle: 40 ° Maximum Slope Angle: 45 ° Elevation: 12000 ft Comments: WE were able to trigger small (D1) wet loose slides on our descent of Notchtop Couloir around 10am. They would run several hundred vertical feet, but only entrain the top few inches of snow that has softened up. By afternoon, these could easily gouge to the ground.

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