We have several resources for teaching about tornadoes in primary schools:
Tornadoes lesson plan for year 3+.
Tornadoes in Your Classroom an article from Primary Geography.
Ideas and lesson plans to enhance the learning and teaching of weather studies in the primary school.
The material is grouped into weather subjects and each subject has two downloadable parts:
Background information and classroom activities The Story for Teachers (links below)
Accompanying images and worksheets – Resources (links below)
Aldridge, V., Meldrum, G. and Ross, H., 2005
The Science of Weather: a primary school resource
City of Edinburgh Council
