Isopleth is a Greek word meaning equal value. It means to connect equal values of a meteolological variable with a line. Often isotherms (lines connecting equal temperature) and isobars (lines of equal pressure) are drawn to help demonstrate weather patterns over space.
Tips to Keep in Mind When Drawing Isopleths
* Draw isopleths all the way to the boundary of the plotted data or until it closes in on itself creating a loop. Do not draw lines for areas you do not have data for.
* Isoplethss never fork, touch or cross one another.
* Adjacent isopleths will tend to look alike. They generally run paralell to one another, as changes are usually gradual.
* Only draw isopleths that fall within the range of pressures reported on a map. If 1032 is the highest pressure reported, then a 1032 mb isobar should not be drawn.
* Always lablel your isopleths!