Wind-compacted snow (wind-skin) encountered above 2,500ft in open and exposed ridgelines ranging from 2-4cm.
Heavy, active NE wind loading with max gusts up to 25mph.
Observation: Turnagain
Location: Tincan
10:30-My partner and I ascended standard approach track with intentions on assessing alpine instability after wind events. We conducted a test pit with at 2,900 ft, assessed conditions and skied a few laps within Treeline. Weather rapidly deteriorated midday above 2,500 ft with increasing north-easterly winds with gusts and limited visibility with heavy snow-transport on exposed ridges. 18-25°F throughout day. Wind event seemed to affect 2,000ft and up the most with obvious wind scouring, wind-skin formation, and lack of tree branch holding snow.
Observer Comments
Weather
10:30-4pm
Overcast skies with Tincan Common obscured after 1pm.
S-1 to S1 after 12:00, with heavy, active snow transport
Gradually increasing Light to Moderate NE winds above 2,500ft. Sporadic gusts of 25mph.
Temperatures ranged from 18-25°F and stayed within 20's in treeline after 1pm.
Snow surface
Fresh snow, that was not exposed to recent wind events, seemed to hold more moisture than 48 hours ago.
Recent wind event created 2-4cm wind compacted (wind-skin) 2,500ft+, that released as localized soft slab on convexities.
Rime developed on stationary surfaces and snow surface at 2,900 ft after 1pm with consistent wind.
Snowpack
Our intentions were to find the MLK jr BSH, and in general, the reactivity of the fresh snow in the alpine.
Overall, the fresh storm snow from 1/28-1/29 is becoming more cohesive, possibly due to wind-compaction and settling as the interface over facets is more pronounced visually, and through snow hardness profiles.
*See Hardness Profile*
Tests:
2,900 ft, NW Aspect, 20°F, 15mph NE Winds, 24° Slope, 243cm snow depth:
CT 19 SP 65cm below surface on 1-2mm Facets
ECTP 20 65cm below surface on .5-1mm Buried Surface Hoar, 1-2mm Facets
ECTP20 65cm below surface on 1-2mm Facets, .5-1mm buried Surface Hoar (decomposing)
CT19 SP 65cm below surface on 1-2mm Facets
2-4 cm wind-affected/compacted top surface layer releasing on convexities. 2,900 ft.
Hardness Profile
2-4mm Facets, Distinct Cups found on ECTP failure layer