How a cloud can stop a launch

We have liftoff! Those three words are music to NASA ears as Artemis has faced a number of delays over the past several weeks. I think we can all understand mechanical concerns, high winds, thunderstorms and hurricanes as launch-blockers. What I didn’t realize until yesterday is that one good healthy cumulus cloud can stop a rocket launch in its tracks! A cumulus cloud? Those puffy, fair-weather innocent-looking clouds against a beautiful blue sky? The kind that don’t even produce rain? Yep. Those clouds.