Rules for Constructing Isolines They connect equal values They should go off the map or form a loop They never Split or Cross They are almost parallel They separate bigger and smaller values

Steps for Constructing Isolines Lightly circle all of the values that are equal to the line you are constructing in pencil Draw light pencil lines between values that the line should be between Connect your circles and your lines Follow those steps and construct the isolines roughly parallel

Temperature and Pressure Isotherms connect equal temperatures and they run across the country from west to east Isobars connect equal pressures and they will form loops around high or low pressure centers