Sawatch

Avalanche

Rich Rogers Drew Gibson · Jan 28, 2024 · Sawatch

Weather

Warm, mostly clear and calm. Light southerly breeze at pass level.

Snowpack

We traveled on mainly W-N-NE-E aspects at all elevations. N, BTL(10,800) had an obvious layer of surface hoar from the cold clear night and the previous warm day with full sun. At this elevation, a thick cohesive slab(1F) rests over very sensitive, weak old snow. In test pits, many columns failed with only a few taps or on isolation. Extended Column Test scores were also less than 10, and Propagation Saw Tests failed at less than half the column length. In this area, though the slab is stout the base is too weak to hold much up. On easterlies near 12,000ft we found variable snow depth from bare ground to 245cm over a few 100ft difference. The thick, cohesive slab at this elevation, failed with easy to moderate propagating results during tests. Multiple old avalanches were observed on the east side of the pass on north and east-facing slopes. Many of the thick slabs we observed above treeline were supportive, but the margins were difficult to identify making travel spooky. On the west side of the pass, there is more snow near treeline, but it is unsupportive in many places making for nervous riding conditions due to ground hazards. In some places, our sleds would break through the slab while stopped and bog in the facets. A pit at 11,800ft on NE aspect showed a similar structure to those on the east side. About half the snowpack is faceted (60cm-65cm or 20"-25") with the same 4 Finger to 1 Finger hard slab sitting on top. Test scores were all less than 10 in Compression and Extended Column Tests. PSTs propagated to the end at 35/100. Near treeline on a SSW aspect the top 10cm of snow was warming in the sun and had become moist. We observed small roller balls off of tree bombs in the area. The water was not soaking into the slab below. The structure was as expected, a firmer slab sitting on weak snow near the ground. The slab was similarly reactive in tests to other areas on the pass.

Avalanche

Multiple old slides from the MLK cycle.