Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
After a relatively quiet weekend weather wise, wind and snow is in the forecast for today and Tuesday. Ridgetop winds bumped up last night from the east and should increase through the day to 20-30mph with gusts in the 40s. Snowfall should be meager with 2-3" in Girdwood, 1-2" at Turnagain Pass, maybe an inch at Summit Lake and a bit more down near Seward 4-8". Snow should fall down to near 300' and cover some of the low elevation bare ground and we'll take that!
Wind Slab Avalanches: With more wind than snow in the forecast, freshly formed wind slab avalanches are our main concern. There is plenty of soft snow on the surface for the winds to pick up and move into new slabs. There is also a layer of surface hoar these new slabs could be forming on, making them more touchy and easier to trigger. In the mid elevations where a few inches of snow sit on a crust, fresh shallow slabs could slide easily on the crust. It's a day to keep our eyes peeled for what the winds are doing. Watch for active wind loading, cracks shooting out in the snow around you, and stiffer feeling snow over a crust or softer snow.
Persistent Slabs: There may be some isolated pockets of unstable snow in the higher terrain. Although much less likely, this could produce a much bigger avalanche than the shallow wind slabs today. One group experienced a large collapse on a layer of buried surface hoar 1.5-2 feet deep in Goldpan Saturday (details here). While we do not believe this is a widespread problem, it is still worth assessing before committing to high elevation steep terrain.
