We also painted storms with watercolor and topped the paintings with a rainbow painted with acrylic on Duralar clear paper. We made batik weather flags by making designs with washable school glue on fabric, painting rainbow colors of watered down acrylic over the glue designs, and then washing the fabric.
This year, I found some old watercolor postcards and used these as well. We looked at several art prints that depicted weather. Then, children painted a weather scene on one side using watercolors and white crayons for resist if they wished. The following day, students wrote a note to someone about the weather. When finished, I displayed the cards front and back under some suspended clouds made by sewing fishing line through batting material and pillow filler. We think the work and the display turned out super!
Enjoy!