I have been lucky enough to get a few of these sort of shots myself at times. They are very satisfying to get. My personal preference is to wait until the whole outline of the dark cloud is fringed with light.
It is always difficult with the sunburst to assess the best time to shoot as it may only last a few seconds and the degree of the sunburst effect can vary a lot in this time, changing suddenly.
This is a lovely shot but then I am a sucker for sky shots without distractions. No horizons or mans clutter, just natures shapes and colours.
A couple of sites if you also love this sort of pic... http://www.meteo.physik.uni-muenchen.de/~paul/nwpej.html http://www.cloudman.com/gallery1/gallery1_1.html
Hey Larry, I sympathize completely. I've seen some clouds out at Point Reyes with shafts of light breaking through and hitting the ocean. Epic. Now that I take my photography more seriously, I ALWAYS have a camera nearby. Even if I'm just going to grab some coffee I bring a camera. Better safe than sorry.
What a coinkidink. I saw this on the random images frame on the left, and was about to click on it, but decided not to, because I get tired of jumping back and forth every time I do this, and what did I see when I scrolled down one more thumbnail? *smirk* Awesome shot, guy. Been trying FOREVER to get a shot like this, but these days, with my crazy schedule, I almost never have time to pack my camera into my van and take it with me, and, wouldn't ya know it, shots like this only come around when I don't have it with me. *growl* Thanks for posting this one, though. It was the kick in the butt I needed to start taking my third eye with me everywhere I go again. :)