A potentially deadly avalanche problem is still lurking at two popular Reno-area backcountry destinations thanks to a weak layer deep in the snowpack.
That’s according to the Sierra Avalanche Center which on Tuesday featured observations from Chickadee Ridge and Tamarack peak along with the daily avalanche advisory.
Chickadee and Tamarack are popular destinations for Reno and Lake Tahoe area residents who enjoy snowshoeing and backcountry skiing and snowboarding.
According to the advisory the persistent weak layer is becoming more difficult to trigger as the snowpack becomes more supportable. But triggering a slide when the weak layer has two to four feet of snow on top of it, “would have very serious consequences and would likely be unsurvivable,” the avalanche center reported.
The persistent weak layer was a factor in a skier-triggered avalanche in a closed area at Mt. Rose Ski Tahoe on Saturday. Located on Slide Mountain across Mt. Rose Highway from Tamarack it shares similar conditions.
The observations from Chickadee and Tamarack came from snow pits on north aspects above 9,000 feet in elevation.
“That would be kind of prime time for some of our current conditions,” avalanche forecaster Steve Reynaud said of north and east facing steep slopes and areas below them near Chickadee and Tamarack.
Pits at both locations showed the presence of the buried weak layer and suggested that fractures could propagate along the snowpack in the event of a break.
“We still have these basal facets near the ground that formed early in our season,” Reynaud said.
While there are portions of Tamarack and Chickadee that are low-angle slopes and not in avalanche terrain, there are some slopes steep enough to slide with runout zones beneath them. And being backcountry destinations with no ski patrol people who visit those places must rely on themselves to know the difference.
More broadly, the advisory identified moderate danger on northwest, north and northeast aspects above, near and below treelike.
With more snow and wind in the forecast wind slabs could grow and the avalanche danger could increase in coming days.
The avalanche center said avoiding risky terrain in the backcountry is the simplest way to stay out of danger.
“Avoiding NW-N-NE aspects steeper than 32 degrees is the simplest strategy for dealing with this persistent weak layer, especially if one has an aversion to or insufficient knowledge of snowpit work,” the advisory stated.
People who are considering backcountry travel in avalanche terrain should have avalanche education, carry safety gear and read the daily advisory thoroughly.
“Our main concern going forward is how big this next storm is going to be,” Reynaud said.