On 12/2 windslabs 6-12 inches deep were found to be very reactive to a persons weight on lee aspects.  The reason for this sensitivity is that new slabs are overlying a weak faceted snowpack in many locations.  This will not only cause windslabs to be more reactive to human triggers, but also be reactive for a longer period of time.  

Windslabs will continue to become deeper as winds continue 12/3 and are likely already be 2 feet deep in certain locations like lee side of ridge lines or cross loaded gullies.  As wind slabs settle and stiffen they may become more stubborn to triggers, but will have the ability to propagate longer distances.  Cautious terrain choices and careful terrain management will be necessary today to travel in areas recently affected by wind.  Watch for signs of windslab that include hard snow over soft, shooting cracks, collapsing and rounded pillowed snow surfaces.  Avoid traveling on large lee slopes steeper than 32°.

The cold and dry weather in November has left us with a weak faceted snowpack.  In areas protected from the wind there is 10-20 inches of dry unconsolidated powder.  The most important thing to pay attention to at the current time is how stiff or slabby the surface snow is.  The stiffer the surface snow is, the higher the likelihood will be for you to trigger an avalanche on terrain steeper than 30°.  In areas where the snow surface is dry and unconsolidated (no slab) the stability has been found to be better although structure is still poor, and human triggered avalanches are possible.  As snow surfaces stiffen human triggered avalanches become likely.  Keep an eye on your partners and only expose one person at a time to avalanche prone slopes.

Don’t expect to find the same snow stability across the forecast area. Re-assess the snowpack every time you are traveling to a new location.  Digging snowpits is a good way to asses a snowpack when persistent weak layers exist.

Photo of 1cm+ chained facet found buried 40 cms (16″) on Catchers Mitt 3500′ SE aspect.