The recent storm snow sits on a buried weak layer 100 cm down. This weak layer may be at a tipping point just waiting for a trigger. Conservative terrain selection is crucial until we have good evidence that the layers have stabilized.
This layer has reached a tipping point. Depending on elevation and aspect, 80-150 cm of snow currently sits above a buried crust from early December. Sugary, facets and surface hoar around the 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. Loose-dry sluffing from steep terrain is likely, especilly when the sun comes out.
An upper ridge of high pressure will generally keep the region cool and dry through the forecast period. A weak temperature inversion may slightly warm ridgetop temps on Thursday.
Thursday/Friday: Mix of sun and cloud. Alpine temperatures near -4 and freezing levels valley bottom -6. Ridgetop wind light from the southwest.
Saturday: Light snow 5-10 cm. Alpine temperatures -3 and freezing levels valley bottom. Ridgetop wind moderate from the southwest.
On Wednesday numerous storm slabs up to size 1.5 were triggered with explosives.
On Tuesday, a widespread natural avalanche cycle up to size 3 was reported from the lizard range. Natural avalanche activity may taper off a bit but the snowpack remains primed for human triggering.
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30-50 cm of recent storm snow blanketed the region by Tuesday morning. Storm slabs will likely remain reactive to human triggers, especially where the wind stiffens the new snow. Deeper slabs will be found on lee slopes due to strong winds.
A persistent slab 80-130 cm thick now sits on the early December crust. This persistent weak layer, with facetted crystals and surface hoar crystals above and/or below it is reaching a tipping point.
Deeper in the snowpack are two hard melt-freeze crusts that formed in November that may have some weak crystals around them. This potential avalanche problem is dormant at this time, however; it remains on our radar.
