Observations

Gulf of Slides Gully 2

March 17, 2021 at 1:00 PM
Name: Jeff Lane
Location: Gully #2, 4800′ elevation

We ascended Gully 2 from the bottom, transitioning from skins to boot packing as the pitch increased. I chose the sunnier side of the gully, climber’s right to boot up. Most of the lower section was 4-5″ of moist windblown snow on top of a stout crust. The top 1″+ was fully saturated with water. Hand shears here required moderate force to pull the slab free from the crust.

As we ascended, we moved out onto a small ridge in the trees. In this location, the windblown snow averaged 8″ on top of the crust and the wet layer was deepening, close to 2″ deep at the time we were there, but the rest of the snow above the crust was dry. Hand shears here dislodged a little easier. Stomping above my boot tracks I was able to pop out 3-4′ slabs 8-10″ deep over the crust.

My final observation was at about 4800′, roughly where the gully opens up into a larger snowfield and about 150-200′ below the top of the gully. We were in a small terrain feature that, in hindsight, was not the best ascent route. This feature was a small ridge and we were on the leeward side of it. Stepping out into a more open, steeper slope I found the windblown snow to be about 18″ on top of the crust. Here, hand shears were easy to pull free and rather than failing on the crust, they failed in a very planar fashion at an interface within the new snow, roughly 6″ deep. Stomping over the tracks I was able to kick out 3-4′ wide slabs, but they didn’t have a lot of snap to them.

At this point, we made the decision to transition to downhill at that location and not risk booting up the final section. We traversed on skis into the gully proper and descended. Turns were heavy with the wet snow but fun. Areas near the bottom that had been wet an hour earlier were starting to turn to crust already in the shade.

Avalanche danger was rated Low today, and I think that was the right call from the limited observations I had (I sometimes pretend to be a forecaster). However, it’s worth remembering the adage that “low danger doesn’t mean no danger.” Looking back at how today unfolded, there are a few pearls worth sharing. First, my ascent route led me to the most sheltered leeward slope in Gully 2, which is exactly where I should have expected deeper drifts of windblown snow from the previous wind event. If I could do it over, I would have either booted up the climbers left side, or possibly gone up the established boot ladder in Gully 1. In either option, I’d have avoided the isolated terrain feature that held the deeper slab. Second, wet slabs can be a dynamic, unpredictable beast (see 4/25/09 or 3/29/14 for examples). Today was the first real warm day these slabs had experienced, which left me with a bit more uncertainty than I care for. Also, I didn’t like how I my boots were punching perforations in the slab down to the crust and the feeling that if even a very small slab pulled free, there was no way I’d be able to escape being carried by the wet heavy snow. Finally, from our vantage point, we had no way to know if any of the other parties in the GOS at the time were below us. Ultimately, the uncertainty in the snowpack and potential consequences of a slide in this specific location outweighed the benefits of getting to the ridgeline.

For what it’s worth, the avalanche nerd in me took 5 minutes to do a quick extended column test at our high point. Bear in mind an ECT is not a very reliable test for either wind slab or wet slab problems. We’d already made the decisions and this was done just to see what would happen. I got ECTN12, Sudden Planar at the interface within the new snow roughly 6-7″ down.