I was about 30 minutes outside of Camp Muir on Mt. Rainier, turning back after a storm induced retreat. Just as I caught a view below me of the tent city, a giant gust of wind smashed into the camp, lifted several tents into the air, and cartwheeled them thousands of feet down the glacier and out of sight. Whoops. Fortunately, it wasn't mine, but lesson definitely learned!
If you’re setting up a tent in the snow, you need a good way to anchor it down. (There’s no such thing as a freestanding tent in a windy place.) Buried trekking poles, skis and rocks work well, as do some sort of a buried deadman. A picket is bomber, but you’ll probably need them for your climb.
Here’s a great choice: 1 gallon ziplock freezer bags. Reinforce the lower sides with duct tape, fill about 2/3 with snow, and seal. Then tie the tent cord around the middle making it into an hourglass-like shape, then bury it. For knots, use a tautline hitch or a trucker’s hitch to fine tune the tension on the tent cord. (See another tip of the week for how to tie these very useful knots!)
So, how strong are they? Answer, more than you think. A study by the French National Guide School conducted some pull testing on various types of deadman snow anchors, and they found that a buried plastic bag could hold a load of approximately 200 kg!
One more option: If you anticipate high winds but no precipitation, you can remove the some all of the tent poles when you leave camp, lie the tent flat, and put some rocks gently on top of it.
Don’t let this happen to you!