We found the same layer buried 3' deep that was the culprit behind yesterday's accident in Smiley Creek, and observed a natural avalanche (maybe two) that likely released on this layer. Snowpack tests show that triggering this layer isn't likely, but certainly possible in steep, wind-loaded terrain. Gusty NW winds were continuing to load leeward aspects.
Skies were overall sunnier than forecast - they began FEW but eventually increased to BKN by afternoon. Late afternoon produced a few blizzardy squalls. Winds were generally light but regularly gusting to moderate and moving moderate amounts of snow. Temps remained cool to cold, especially in the shade, but the sun this morning was sufficient to but a soft crust on SE aspects.
Feb 18, 2021
(+/- 1 day)
Feb 17, 2021
(+/- 3 days)
Glassed the Sawtooths with good light this morning, and saw surprisingly little slab avalanche activity. Loose snow avalanches were widespread, but nearly all were D1 in size - see photo.
The morning sun moistened the top 5cm or so (at least on SE), and had already turned to a soft crust by mid afternoon. HS at mid to upper elevations averaged from 180-230cm. 12/11 was probed at around 170-180cm down.
@N, 9200': HS 230cm. No discernible weak layers in top 120cm except old wind layer from early Feb. ECTX.
@SE, 9300', 35*: HS 180-190cm. 1/27 facet/crust layer down 1m, slab ranged from F to P at base. Produced ECTP x3 on nonstandard loading steps (see video). 2/11 down 70cm gave ECTP30.
Layer Depth/Date: 100cm
Weak Layer(s): Jan 27, 2021 (FCsf)
Comments: Rose indicates observed terrain. ECTPs with nonstandard taps, older natural avalanche.
We observed active wind loading and got some isolated cracking in small drifts, but you would have needed to be in bigger and more exposed terrain to have encountered a wind slab problem.
We avoided consequential slopes over 35 degrees.