Vail & Summit County
SnowpackDrew Gibson · Feb 23, 2023 · Vail & Summit County
Weather
Throughout the day temperatures warmed from the teens into the twenties. There were short periods of sun and S1 snowfall. Cold and windy at ridge crest with some snow transport (the little that had not blown away from above treeline).
Snowpack
I travelled up westerly aspects under partly cloudy skies. Air temperature at the trailhead was 13F at 10:00am. Winds were light and swirling. Below treeline there was 10cm-15cm of new snow on old tracks. The trees had only a few centimeters of snow on them and open areas near creek bottom had signs of wind effect. Approaching treeline I observed up to 25cm of new snow in places. At and above treeline the winds were 15-20 mph with gusts well into the 30s and out of the west southwest. Upon reaching ridge crest I observed fresh cornices on aspects lee to the west southwest. During a period of brief visibility onto steeper (>35 degree) northeast and east facing terrain it appeared the recent wind load was farther down the slopes. Along the saddles, lower angle terrain with similar aspect, was wind stripped close to the ridge. Small fresh cornice failures had no obvious effect on the aprons and no signs of recent activity were noted. Despite the wind speeds during this storm there is up to 25cm of new snow just below treeline on the windward aspects. South, southeast and southwest aspects were heavily impacted by the sun in the week leading up to this current storm. The strength of the melt freeze crust that formed is variable. In places it is not breakable while on skis and very difficult to break with the handle of a ski pole. In cross loaded areas where the melt freeze crust exists, there was 10cm-20cm of new snow. The new snow seems to be bonding well with minimal sluffing on hard turns. No cracking was observed. Similar conditions were observed on the limited southeast facing terrain that I travelled on. The weather was a mixed bag this afternoon with brief periods of rapid snowfall, sun and gusty winds. Periods of snowfall were short. Temperatures were not warm and there was no new sun effect. Inspecting northwest facing terrain near treeline I found over 150cm of snow in most places. New snow totals were variable due to wind effects. Pit data showed 29cm of soft new, and wind-blown snow resting on a variety of relatively harder layers. Regrettably, this is resting over 52cm of chained depth hoar which is very weak. Pit tests had low to moderate scores, CT11 and CT12 respectively, with sudden planar failures on the depth hoar layer at 52cm. An Extended Column Test yielded no results but on an extra tap from the shoulder (31 taps), the column had a propagation on the depth hoar layer at 52cm, quickly falling into the pit and attempting to knock me over. Given the strength of the mid pack and the depth it seems unlikely to cause a failure in the basal facets, but it cannot be ruled out completely. Below treeline even in open areas the wind had minimal effects through the day, I was able to pick up my skin track from the morning and it was not drifted in.