Come dressed for the occasion with a perfectly appropriate tee-shirt and/or set of slides, overheads, computer graphics, and / or videotapes. Whatever it takes to get a weather discussion "off the ground".
Tell students you'll be talking about how air moves up and down in the atmosphere.
Ask students what they know, what they want to know and (at the end of the day) what they have learned about the ups and downs of weatherÂ….also known as a KWL chart
Introduce the concept of STABILITY .. and follow that with a series of demonstrations and hands-on activities to showcase cloud formation both vertically and horizontally. Blend these with comparisons to cloud photographs from the ground and air and satellite images. For good measure, add some sounding analysis (bringing a radiosonde balloon if you have one).
Close with applications to classrooms and home (hot ceiling and cold floor; 2nd story warmer; fire and smoke - where to go for safety?, etc). Talk about the recent tunnel fire in Swiss Alps and which way was the best way to escape.