Small wind slabs are forming at the surface but our main concern remains the persistent weak layer down 30-60cm.
Excellent skiing can be found in locations sheltered from the wind.
Winds have varied in direction so be on the lookout for reverse loading. Fresh windslabs are thin but they may be enough to trigger the persistent slab hiding 30-60 cm deep.
The Jan 7 persistent weak layer of surface hoar has been found in profiles both at treeline and in the alpine buried up to 60cm deep. Test results suggest that propagation is still possible on this layer. Expect more reactivity on southerly aspects where multiple crusts exist in the upper snowpack,
Explosives testing on round hill ridge on Tuesday produced Size 1.5 Wind slabs averaging 10cm deep.
A persistent slab avalanche was reported by a third party in the Kors-Thomas bowl of Avalanche Mountain on Sunday. No details of the event are available but it appears to have been skier triggered.
Periods of moderate wind creating fresh wind slab at the surface. Sheltered areas have ~15cm of cold, faceted snow sits atop a denser, wind-pressed layer. Below this lies a weak interface (Jan 7th layer) down 30-60cm, comprised of surface hoar (all aspects) and or a thin crust on steep S aspects.
In the start zone of Mt Fidelity, moderate "resistant" & "sudden planar" snowpack test results were found on the Jan 7 layer.
Tonight Clear periods. No precipitation. Ridge wind NW 20-30 km/h. Freezing level (FZL) at valley bottom.
Wednesday A mix of sun & cloud. No precipitation. Alpine high -8. Ridge wind W 15-25. FZL 600m.
Thursday Mainly cloudy with isolated flurries. Trace precipitation. Alpine high -8. Ridge wind W 20 gusting to 45. FZL 700m.
Friday A mix of sun & cloud. No precipitation. Alpine high -11. Light ridge wind gusting to 35
Thursday