TORNADOES

This volume in the Dangerous Weather series will discourage all but the most intrepid of budding meteorologists. Small, dense type and a difficult, specialized vocabulary combine for some college-level discourse: ``Diverging air, flowing away from an area of high pressure, or anticyclone, has negative relative vorticity and provided the divergence continues at a constant rate, its absolute vorticity decreases eventually to zero.'' A single paragraph introduces planetary vorticity, vorticity of the moving stream, relative vorticity, absolute vorticity, cyclonic motion, positive vorticity, anticyclonic, and negative vorticity. The title may act as a supplement to curriculum-planning, but it's impossible to imagine students settling into this one on their own. (b&w photos and illustrations, not seen) (Nonfiction. 14+)