A while back, when we were under a tornado warning, I took granddaughter Kaedyn into the bathroom in the center of the house, since we had no basement. To get her mind off of the storm, the only thing handy was shaving cream. So we covered the counter with lather and drew in it and then pretended to be Santa by giving ourselves white beards.
I read where another Mom took her daughter's mind off the storm's frequent lightning by having her girls strike a model's pose, pretending that the flash came from a camera.
Do you have any tricks for taking kids' minds off of a tense situation?