A melt-freeze cycle affecting the surface of the snowpack has left a widespread crust after the weekend, now buried under 10 cm of new snow. This freezing has reduced the likelihood of avalanches in all areas except northern aspects above 2100 m, where the snow remained dry, and human triggering of a persistent slab remains possible.
Over the weekend, Persistent slabs up to 60 cm thick were reactive on two different weak layers; natural avalanches were widespread. Now, with 15 deg of cooling in 12 hours, the wet snow has refrozen and these slabs are less reactive. Triggering remains possible in areas that did not melt/freeze.
Other than some small dry loose sluffs in steep terrain (new snow running on a crust), no new avalanches were observed or reported today.
This follows a very warm weekend avalanche cycle where we saw widespread natural and explosive-triggered avalanches running as persistent slabs. This activity has now ended with the onset of colder temperatures and some new snow.
The top 50 cm of the snowpack is complicated.
10 cm of new snow, over a Mar 2 crust, over a cohesive slab, over Feb 22 and Jan 30 weak layers, over a faceted mid-pack, all on top of basal facets. Way too complicated to predict anything, except that the temperatures have dropped 15 degrees in 12 hours, which is a stabilizing trend. Don't overthink the snowpack, it's structurally weak, even when stable. Instead, use your terrain and group management skills.
After a brief interlude with an upslope storm (easterly flow), which dropped the temperature 15 degrees in 12 hours and deposited 5-10 cm across the region, we now return to a more traditional SW flow on Tuesday. Expect mostly clear skies on Tuesday, with light winds from the SW and treeline temperatures ranging from -5 to -9. Freezing levels rise to 1700 m and expect the temperature to spike anytime the sun comes out.
