Storm Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
This series of cold spring storms is keeping winter alive this week. Seward weather stations are having a hard time keeping track, but it looks like there was 4 to 6" of new snow overnight above 1,000' with some moderate winds bringing the storm slab depth to 2' or more in those areas that recieved the most snow since Friday. Fresh wind slabs formed last night as wind speeds bumped up blowing the new snow into pillows. It's hard to say how touchy this new snow will be today, but a storm or wind slab avalanche could be very large if a person were to trigger one. The safest option is to give the snowpack more time to adjust and stick to low angle slopes today.
Today is a good day to be in assessment mode if you are wanting to get onto steeper slopes. The new snow is so deep that one of the best tools may be small test slopes that have no consequences if they fail. Shooting cracks indicate there is energy in the snowpack and it needs more time to adjust. It has cooled off enough that dry loose may be another problem today to add to the list.
Storm totals below are from 12 AM Friday morning through 6 am this morning:
- Portage: 11.4" Snow Water Equivalent (SWE), equaling 6 to 9' snow above treeline.
- Girdwood: 5.2" SWE equaling 3' snow.
- Turnagain Pass: 3.2" SWE equaling 12-30" snow.
- Summit Lake: 0.9" SWE equaling 6-8" snow.
- Seward/Lost Lake: 2.9" SWE equaling 16-24" snow.
Cornice Fall: Cornices could release naturally today or be triggered by a person. A cornice fall could trigger a large slab avalanche below so keep this in mind while traveling below or above these looming giants.
(4/8/2025)
Storm slabs on Penguin Mountain above Girdwood. Similar storm slab avalanches could be occurring in the Seward area.
Photo: Caleigh Warner