Observation: Hatcher Pass

Location: Valley of Sin between 4068 and peak 4600

Route & General Observations

We toured up the Valley of Sin towards Women’s run and ascended to the ridge between peaks 4068 and 4600. We did one lap near Women’s Run and then went back to ridge and started up 4600′. Visibility deteriorated rapidly so we exited off of the shoulder back into Valley of Sin and to the road.

Overall travel was easy and soft, with last weeks snow nicely settled into a supportable slab. Some surface hoar and recrystallized snow was observed on the surface of sheltered, shady slopes, along with a very thin refrozen crust on some aspects likely due to a period of high humidity with convective fog on Tuesday.

We didn’t travel on many solar aspects but where the slope tilted more towards the sun crusts appeared to become more thick and firm.


Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Observer Comments

No collapsing or cracking observed. No recent avalanches observed today on our tour.

Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.

The day started off pretty spectacular with great vis and moderate temps (16º at 4500’ at 10 AM). This held until around 1PM when clouds rolled in with some wind and a few snowflakes. Temps at 4500’ peaked at 21º at 2PM.

Snow surface

Snow surface is pretty good. There is about 8’’ of decomposing new snow and graupel on top of the old variable thickness, generally supportable, crust. Some places there was enough wind transport during the storm to have blown clean to the crust or only have a couple inches new snow, however, those areas are specific and fairly predictable. (Ridges, sub ridges ,ect) Northerly slopes have a soft surface where as some southerly slopes have a very thin zipper crust. At least where we were today the crust did not seem thick enough to affect ski quality.


The current concern in the snowpack now is how the new snow bonded to the old crust. In places where the crust is smooth and the new snow consolidated we have a good avalanche setup. In our pit which had this setup we had propagation in both of our ECT tests. The good news is both the old crust and weak layer is relatively variable which helps interrupt slab continuity. See youtube link for video of ECT test.
See pit profile

Photos & Video
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