An isobar is a line on a map connecting points having the same atmospheric pressure at a given time or on average over a given period.
Answer: CONTINENTAL TROPICAL AIR MASS. The source region for cT air is the desert Southwest, the high plains and Mexico with relation to the United States. The air has low dewpoints and warm to hot afternoon temperatures but with mild nighttime temperature. Skies are generally clear in cT air
Explanation:
C. The area of the US doubled
