Yosemite Forum

Thunder & Lightning on Half Dome?
Author: Jeff Mullins (---.client.comcast.net)
Date: 07-12-04 16:15

When thunder clouds start building above Yosemite Valley, what does a summer hiker do--other than pray--when he or she has just mounted Half Dome and lightning bolts start erupting between granite and sky?

I understand the WORST thing a hiker can do, of course, is open an umbrella. But what are the other do's and don'ts that keep one from going "poof?"

You shouldn't have just summitted Half Dome if lightning is going to come in. If there's any sign of thunder and lightning then you should turn around immediately and seek refuge in the forest. Above all, you need to get off exposed granite, as that is basically a lightning rod. The standard advice is to take cover under a uniform grove of trees (specifically young enough that a blast won't fell one of them onto you). You're supposed to crouch to present as small a target as possible. Also, while crouching you should be on your toes to limit contact with the ground or granite.


If you're interested in a story of guys being on Half Dome when they shouldn't have been up there in a lightning storm, check out Bob Madgic's book "Shattered Air"

Generally speaking, its safer to start hiking Half Dome very early in the morning, so you can reach the summit and start descending before those afternoon thunderstorms roll in.