Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
On Monday I observed reactive Wind Slab just below the ridgeline of Tumalo Bowl (East, near treeline). At this time of day there was only 7cm. of new snow and these Wind Slabs were shallow (20 cm.) and small. For the past few days snowfall forecasts have been a bit optimistic and snow showers have under-delivered.
Current forecasts for Monday night and Tuesday are totalling 15 cm or so. Winds will be Moderate or Strong from the West and Southwest. If we do receive 15 cm. of new snow, Wind Slab avalanches could be large enough to bury or injure a rider (D2) in isolated terrain. Additionally Wind Slabs will be large on slopes with a particularly large fetch, or physical area from which the snow can be blown.
Monitor how much snow is on the ground in sheltered locations, and then evaluate the Wind Slab problem on less steep, or smaller lee slopes. Today the Wind Slab problem was pretty apparent: I could see widespread blowing snow, extensive recent cornice growth, and lots of cracking in the 20 cm. or so of windblown snow on East slopes.
(4/17/2023)
D1 Wind Slab in Tumalo Bowl (East, near treeline)
Photo: Gabriel Coler
