A widespread avalanche cycle occurred in response to the recent storm. Large storm slabs remain primed for human triggering on Wednesday. Conservative terrain selection is crucial as the snowpack slowly settles and stabilizes.
This layer has reached a tipping point in parts of the region. 70-110 cm of snow currently sits above a weak layer from early December. Combinations of sugary facets , surface hoar and/or a crust mean persistent slabs are likely reactive, especially to human triggers.
Storm slabs will likely be reactive and require patience and time to settle and stabilize. These may be extra touchy on lee slopes where wind loading has built deeper slabs. Simple, low angle terrain away from overhead hazard is a good choice right now.
Loose-dry sluffing from steep terrain is likely, especilly when the sun comes out.
A high-pressure system off the coast will bring generally cooler, more seasonal-like temperatures and clearing to the region.
Wednesday/ Thursday: Mainly sunny and alpine temperatures near -4. Ridgetop wind 50km/hr from the West. Strong alpine temperature inversion. Freezing levels valley bottom.
Friday: Cloudy with sunny periods. Alpine temperatures near -8 and freezing levels 1500 m. Ridgetop wind light from the southwest.
Widespread natural avalanche activity up to size 3 was reported through the region on Tuesday. Natural avalanche activity may taper off a bit but the snowpack remains primed for human triggering.
Please consider sharing your observations on the Mountain Information Network. Thank you to those that have already submitted this winter!
30-50 cm of recent storm snow blanketed the region by Tuesday morning. Storm slabs will likely be reactive, especially where the wind stiffens the new snow. Deeper slabs could be found on lee slopes.A persistent slab 70-110 cm thick now sits on the early December crust. There is increasing evidence that this persistent weak layer, with facetted crystals and surface hoar crystals above and/or below it is reaching a tipping point and susceptible to human triggering and step down avalanches from recent storm snow.
The base of the snowpack consists of a hard melt-freeze crust from early-November that may also have weak crystals around it. There has not been recent avalanche activity on this layer but it remains on our radar. The most likely spot to trigger it would be on thin and rocky slopes or, like above, from step down avalanches in the recent storm snow.
