Vail & Summit County
SnowpackDrew Gibson · Mar 9, 2023 · Vail & Summit County
Weather
Mostly clear with passing clouds through the day. Wind speeds were light to moderate with gusts over 30 mph at times. Wind direction was mostly west but was swirly at times. Temperatures were warm and felt above freezing though the wind kept thing cool.
Snowpack
Below treeline slopes with no tree cover that are on the southerly half of the compass have a thin melt-freeze crust on the surface. Traveling on mostly east aspects below treeline I found a shallow (around 1 meter), mostly supportive snowpack even in areas where there has been no compaction. Near treeline the wind speeds picked up and were gusty with periods in the 30 mph range. The snow surface near treeline on the southerly half of the compass is a mixed bag. There are places of stiffer wind-loaded snow and more sun-affected snow. Gullies and drastic terrain features had stiff wind-loaded snow on the leeward sides. During the tour the winds were mostly out of the west with many snow-tornados observed on above treeline slopes and at ridge crest. Above treeline some direct south-facing slopes had bulletproof melt freeze and wind-affected snow making skinning slippery. Many above treeline slopes are buffed smooth from the wind. In my travels, the surface snow was nearly impenetrable in many places even with a probe. On the edges of wind-buffed terrain features (like gullies and rollovers) the snow was much shallower and even unsupportive at times. The wind-affected surface snow varied greatly across the north-to-east through southeast aspects. Digging on easterly aspects near treeline the easterly aspects have more snow and have been affected by the sun more and the top 10cm of snow are showing signs of warming. The recent warm-up has created a complicated layering structure with melt-freeze crusts and small facet layers in the upper levels of the snowpack. The mid-pack and the lower layers on these aspects are still persistently weak but seem to be gaining strength. Test scores are still low to moderate in the deeper layers, but I am not seeing propagation at this time. On northeast slopes near treeline, the snowpack has not been affected by the solar gain and where I dug, has a shallower and weaker snowpack. Where I traveled the snowpack in this elevation band seems to have fewer stiff mid-pack layers and overall less depth (around 1m). Test failures were low to moderate with sudden planar results on both Compression Tests and Extended Column Tests. It seems the near treeline slopes on the more easterly side do not have the stiffer and more supportive upper snowpack layers that will hold up more weight.