Sawatch
AvalancheAIARE ITC · Feb 10, 2020 · Sawatch
Weather
Increasing sky cover from scattered to broken, mostly calm with periods of light wind out of the northwest with localized drifting snow, no precipitation, air temperature at 13:00 was 23 F.
Snowpack
Groups felt whumphing and observed a propagating crack (~200 ft) across the full extent of a SSW micro terrain feature near tree line at 11,100 ft. From three test pit locations on NE aspects at 11,100 ft, the height of snow ranged from 120-135 cm, with 10-12 cm of new snow and with the Feb 3 FCsf buried down 45-55 cm. Snowpack tests revealed both sudden and propagating results on a variety of layers in the different pit locations. On the Feb 03 FCsf (2.0 mm) we observed an ECTP and PST 40/100(end) down 55 cm. Below the Feb 2 MFcr, we observed an CTH SC, ECTP, and PST 30/100(end) down 60 cm. On the depth hoar at the ground, we observed an CTH SC and ECTP.
Avalanche
The groups observed two avalanches. A D1.5 from the previous 24 hours (suspected natural) on a NNE aspect at 11,200 (see photo). One group observed a D2 on a NW aspect and cross-loaded feature near tree line that was thought to have released naturally during the day as it went unnoticed during departure and appeared to have a clean crown when observed on the return trip.