I found some nice slabby snow and set up a quarry, carefully cutting out bricks of snow and building a wall along the windward side of the tent to help protect it from wind. Truth be told, I was pretty proud of it - nice and clean, it would block the wind but potentially deposit more snow in its wind shadow (our tent).

After cooking dinner, we crawled into the tent calling it an early night so that we'd be well rested in the morning.

And then everything went to shit.

About an hour after we crashed, the wind picked up. Gusty breezes turned into blustery wind. And then we started hearing snow falling on the tent. And then the wind was howling and the snow was pounding the tent. Before long I was lying in the tent wondering if it was going to collapse. I mean, it was a really light tent.

Luckily, that wall I'd built provided enough protection to let the tent survive. The problem was that we were still getting a bunch of wind and the low pressure air shadow of the wall caused the snow to swirl around. Swirl around and sneak under the edge of the fly. When you've got a tent with 100% mesh walls and snow sneaking under the fly, it turns out it comes right on into the body of the tent.

My first inkling that we might have a problem was when I started feeling a refreshing mist on my face. In the dark though, it was hard to tell exactly how bad it was.

In the morning, it became obvious. While we were warm and happy in our sleeping bags - about a 2-3cm of snow had accumulated in the tent. Pro Tip: If it's snowing inside your tent, you have fucked up. In our case, we could have either picked a campsite suitable to the unsuitable tent we brought (Motel 66 or dropping down to a safe spot on the Matier Glacier below) or brought a tent suitable to the conditions we faced. We didn't even need a winter tent - a 3 season tent with a slightly burlier inner would have been fine.