One morning this week it absolutely stormed. The sky was so dark I had to turn the lights on on the back porch.
To engage the three, I pulled out stickers, markers (they said washable, they certainly were not), crayons, and paint. I even cut their initials out of a potato so they could stamp their initials onto the paper. That didn't work well--at all.
But, they did enjoy putting the markers into their paint and rubbing them all over everything. It was a fun morning, listening to the rain and thunder and making "thank you" cards.