| A | B |
|---|
| troposphere | The bottom layer of the Earth's atmosphere |
| thermosphere | The upper layer of the atmosphere where temperatures are extremely high |
| mesosphere | The layer of atmosphere where air is thin and most meteors burn up |
| stratosphere | The layer of the atmosphere in which ozone is present |
| air mass | A large body of air that has the same characteristics throughout |
| air pressure | The weight of air pressing down on an area |
| relative humidity | A comparison of the actual amount of moisture in the air to the greatest possible amount that could be in the air at the same temperature and pressure |
| front | The border between two air masses that collide |
| forecast | A prediction of what the weather will be like in the future |
| station model | An arrangement of symbols and numbers that show the weather conditions recorded at a weather station |
| surface map | A map that includes station models and information about fronts and about centers of high pressure and low pressure |
| weather balloon | A balloon released into the atmosphere that carries a package of instruments that records data about temperature , air pressure, and humidity |
| weather map | A map that shows data about recent weather conditions across a large area |
| thunderstorm | A very strong storm with a lot of rain, thunder, and lightning |
| hurricane | A large, spiraling storm system that can be as much as 600 km across |
| tropical storm | The stage of hurricane development when the winds of a tropical depression reach a constant speed of 63 km/hr (39 mph) |
| tornado | An intense windstorm that often forms within a severe thunderstorm |
