Avalanche warning in effect for Grand County
December 26, 2017
An Avalanche Warning is currently in effect for all of Grand County, the entirety of the Front Range avalanche forecast zone, and most of the I-70 corridor including Summit and Vail counties after a series of intense snowstorms slammed into Colorado's north central mountains over the weekend.
The warning was issued by the Colorado Avalanche Information Center early Tuesday morning and extends from 6 a.m. on Dec. 26 through 6 a.m. Dec. 27.
"Very heavy snowfall on Monday and continued strong westerly winds have combined to create very dangerous avalanche conditions," reads the warning from the CAIC. "Human triggered avalanches are very likely. If you trigger an avalanche today, it will be large enough to bury or even kill you. Travel in or below avalanche terrain is not recommended."
A summary of the dangerous conditions by the CAIC explains that strong winds are blowing snow and causing drifts in, near and above treeline and that the new wind-deposited snow is forming "touchy slabs on top of an extremely weak snowpack.
“You can trigger avalanches in the new snow layers in all elevation bands, including below treeline areas."
The CAIC's warning about avalanche danger today stressed the potential impacts of a snow slide.
"If you trigger an avalanche in the new snow, it could be large enough to bury or injure you," reads the CAIC summary. "It has the potential to step down to deeper buried weak layers or even to the ground. These avalanches will be large enough to kill you."
The CAIC summary also notes that avalanches could be remotely triggered today from adjacent slopes or even from below.
"Shooting cracks and collapsing are a sign that the deeper weak layers are failing under your weight," states the CAIC. "If you encounter these conditions, you should find a different less steep place to travel and avoid crossing under any avalanche terrain."
To avoid the danger the best bet would simply be to stay home but if travel is necessary the CAIC recommends sticking to slopes, "with a slope angle of less than about 30 degrees and avoid traveling on slopes where there is steeper connected avalanche terrain above you."
Currently the CAIC has an avalanche danger forecast of "High" for areas above treeline in Grand County, "High" for areas near treeline, and "Considerable" for areas below treeline.
The CAIC defines "High" avalanche danger as, "Very dangerous avalanche conditions. Travel in avalanche terrain is not recommended." The CAIC defines "Considerable" avalanche danger as, "Dangerous avalanche conditions. Cautious route-finding and conservative decision-making essential."
The CAIC has identified both persistent slabs and storm slabs as specific avalanche problems for the day. Persistent slab avalanches are forecasted for northwest, north, northeast, east, southeast, and south facing aspects above and near treeline. Persistent slab avalanches are forecasted as "Very Likely" today and the CAIC forecasts any likely persistent slab avalanches as being "Large" in size.
Storm slab avalanches are forecasted for northwest, north, northeast, east, southeast, and south facing aspects above, near and below treeline today. Storm slab avalanches are forecasted as "Likely" today and the CAIC forecasts any likely storm slab avalanches as being anywhere from "Large" to "Small" in size.