The storm ended last weekend, but large and destructive avalanches are still possible. Remain conservative in your terrain selection.
Confidence
Poor - Due to the number of field observations
Weather Forecast
A ridge of high pressure will maintain mainly dry conditions for Wednesday and Thursday. For both days, expect a mix of sun and cloud with very light flurries and alpine temperatures of about -9. Winds should be light to moderate from the northwest on Wednesday switching to light and southwesterly by Thursday. A moist and warm southwest flow will bring snowfall to the region late Friday with freezing levels creeping up to about 1500m.
Avalanche Summary
A widespread natural avalanche cycle to size 3 was reported to have occurred last Friday and into Saturday. Since then we have had no new reports of avalanche activity. This may speak more to a lack of observations rather than actual conditions.I suspect avalanche activity on these deep layers will be less frequent, although the potential consequences of a release continue to be severe.
Snowpack Summary
Remote wind data suggests 10-20cm of recently fallen snow may have been pushed into wind slabs in exposed terrain. Below this you'll likely find a hard rain crust. In the Golden area this crust exists up to around 1600m, whereas in the south it is up to 2000m or higher. In total, last week's storm produced slabs up to 1m thick in the north of the region and around 60cm thick in the south. This slab sits on the mid-November weak layer (surface hoar, facets, and/or a crust). Below this you will likely find a 15-20cm thick layer of sugary facets, which is sitting on a solid rain crust from early November. Reports of whumphing and remote triggering on these layers suggests a persistent weakness with the potential for large propagation and large avalanches.
Problems
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.