Safely triggered a very small fresh windslab above our ski line in a narrow gully feature. At the deepest, the crown was 8" deep and 10 feet wide. As the slab released, it entrained soft snow and ran about 50 feet down hill. See included photo for slab and crown image.
Observation: Hatcher Pass
Location: Peak 4,600' and April Bowl
Toured up from the Fishhook lot to the Valley of Sin, up the Women’s Run saddle and to Peak 4,600′ to assess wind speeds, direction and any signs of blowing snow creating new slabs in the upper snowpack. The day started with flat light and cleared to high, wispy cirrus clouds and ridgetop plumes. Clear signs of wind transport and loading were observed just below ridgeline in the later afternoon as winds came more consistently out of the E/NE.
We later snowmachined up to Hatcher Pass proper to April Bowl from the Hatcher Pass Lodge lot to assess the Willow side of the pass.
Avalanche Details
Obvious signs of instability
| Recent Avalanches? | Yes |
| Collapsing (Whumphing)? | No |
| Cracking (Shooting cracks)? | Yes |
Observer Comments
We saw some very small sluffing below high marked snowmachine tracks and a few small (D1) recent wind slabs. Shooting cracks were only observable on recently windloaded, ridgetop terrain. No whumping was observed today.
Weather
No new snow since 2/24.
Cold (2* F on Marmot summit @1400), partly cloudy>mostly sunny by the midafternoon afternoon with good visibility.
1100-1300: Calm-light E breeze.
1300-1500: Light gusting moderate E/NE winds. Clear signs of snow transport at ridge tops (see photos)
Snow surface
Northerly aspects had mostly soft foot+ deep snow. Higher up at ridge level, snowpack is shallow and rocks are showing. Just below ridgelines and on lee and crossloaded aspects, evidence of thin 1" wind skins and deeper 6"+slabs apparent (see photos). Snow surfaces are faceting nicely.
Snowpack
Snow is staying generally soft below the upper elevations. We skied nice, boot top powder after descending to below 4,000' all the way back to the up track to return to Fishhook lot. Below the new snow, small 1mm near surface facets were observable with the naked eye. No formal pits were dug today. We focused on moving quickly through lots of terrain to observe new wind slab formation, distribution of wind slabs, and surface snow conditions.
Light winds had already filled in skin tracks and clearly moved snow around.
Wind effect at upper elevations (4,000'+)
A recent natural windslab avalanche in April Bowl.
3.1 Plumes at ridgetop observed on Arkose ridge today
3.1 Small recent wind slab on Punk Spines N 3700'
3.1 Firm wind hardened surfaces exist on many ridgelines, near peak 4600'
3.1 Shallow isolated cracking from recent wind slab formation at ridgeline bwtween Women's run and peak 4600'
3.1 Highmarking tells us something about stability on Bullion Mtn on the Willow side SE 4200'
3.1 Highmark triggers small avalanche on SE aspect of Skyscraper 4000'
3.1 Human triggered small wind slab N 4500'