| A | B |
|---|
| weather | condition of the atmosphere at a particular time and place |
| water cycle | continuous movement of water from water sources into the air, onto land, into and over the ground, and back to the water sources |
| humidity | amount of moisture in the air |
| relative humidity | amount of moisture in the air compared with the amount that the air can hold when saturated |
| condensation | change of a gas to a liquid |
| dew point | temperature when air will be 100% saturated |
| cloud | collection of millions of tiny water droplets or ice crystals |
| precipitation | solid or liquid water that falls from the air to the Earth |
| evaporation | change of a liquid to a gas |
| transpiration | process by which plants return water vapor to the air |
| saturation | point at which air will hold no more moisture |
| air mass | large body of air that has similar temperataure and moisture thoughout |
| front | boundary that forms between two different air masses |
| thunderstorms | small intense weather system that produces strong winds, heavy rain, lightning, and thunder |
| lightning | large electrical discharge that occurs between two oppositely charge surfaces |
| thunder | sound that results from the rapid expansion of air along a lightning strike |
| tornado | small rotating column of air that has high wind speeds and low central pressure and that touches the ground |
| hurricane | large rotating tropical weather system with wind speeds of at least 119 km/h |
| thermometer | tool used to measure temperature |
| barometer | tool used to measure air pressure |
| windsock | cone shaped device used to measure wind direction |
| wind vane | like a windsock this is a tool used to measure wind direction |
| anemometer | tool used to measure wind speed |
| isobars | lines that connect points of equal air pressure |
