Without a table or graph, you might forget what an equation represents.
The grassland of North America is a "steppe climate" in fact in Russia grasslands are called Steppes. This climate makes us prone to WEATHER from high pressures and low pressures meeting up and not liking each other very much - Lightning, Hail, Tornados, Floods, and in the northern parts Blizzards. Basically Winds and Clouds are what we watch and monitor - beautiful, dangerous, and can go from benign to ferocious in the blink of an eye. Weather can kill and weather can be a salvation. It depends on the whims of pressure.
Two that I know of are a sextant, and maybe an astrolabe
