Special Avalanche Advisory in effect for Grand County
January 20, 2019
Danger is high in the Colorado backcountry this weekend as the entire state of Colorado remains under a special avalanche advisory following weekend storms that deposited several inches across most of the Rocky Mountains.
As of Sunday morning all 10 of Colorado's avalanche forecast zones, including the Front Range forecast zone that includes Grand County, were under a special avalanche advisory. The special avalanche advisory was issued early Saturday morning and remains in effect until 8 p.m. Monday night.
"A special avalanche advisory is in effect for the mountains of Colorado through Monday, January 21," stated avalanche forecasters from the Colorado Avalanche Information Center. "Avalanche conditions are dangerous. Backcountry travelers can easily trigger very large and deadly avalanches."
Officials from the Colorado Avalanche Information Center, or CAIC, went on to note that avalanche triggered under current conditions may break across terrain features and could run long distances before coming to a stop. According to CAIC representatives a total of 10 people have been caught in avalanches since Jan. 11. Overall the CAIC has tallied 44 human triggered avalanches in the backcountry during the same time-span. The CAIC had recorded a total of 280 total avalanches across the state over the past nine days.
"Backcountry travel this weekend will require conservative decision making, cautious route finding, and careful snowpack and terrain evaluation," CAIC forecasters said.
The avalanche danger in all 10 forecast zones was rated as considerable on Sunday as well. For Grand County, and the larger Front Range forecast zone, the danger level is rated as considerable above and near treeline with the danger level dropping to moderate below treeline. The CAIC breaks avalanche danger down on a five point scale running from low, level one, up to extreme, level five.
"Slopes near and above treeline covered in wind-drifted snow are the most dangerous," said officials from the CAIC. "Look for cornices and long linear drifts behind trees or rocks to determine recent wind directions. Westerly winds were very strong, and snow drifted lower than is usual on many slopes. Steep slopes below ridges, tucked under cornices, or those that appear smooth and rounded are the slopes you should treat with suspicion."
Forecasters from the CAIC noted that avalanches that do occur in the drifted snow could potentially break deeper weak layers of snow and in turn take out most of the snowpack on a given slope.
"Avalanches that break on buried weak layers will be larger, harder to predict and can run long distances," forecasters said. "You may trigger slopes from below or a long distance away. Use an extra margin of safety in your terrain choices today."
The CAIC's in-depth forecast on Sunday noted two different avalanche problems today: wind slabs and persistent slabs. According to the CAIC wind slab slides are most likely on north, northeast, east, southeast and south facing aspects above and near treeline. The CAIC rates such avalanches as likely and predicts that any wind slab avalanches kicked off today will be large in size.
The CAIC's forecast for persistent slab avalanches notes they are most likely on north, northeast, east and southeast slopes above, near and below treeline. The CAIC rates such avalanches as likely today and predicts that any persistent slab avalanches that do occur will be large in size.
Sunday's special avalanche advisory comes after one of the deadliest weeks of the season so far in terms of avalanches. A backcountry tourer was caught and killed in an avalanche in Utah on Friday. That was one day after an inbounds avalanche at Taos Ski Valley in New Mexico caught two skiers, killing one while severely injuring the other.