| A | B |
|---|
| median | the middle number |
| mode | the number that occurs most often in the data |
| range | the difference between the highest and lowest number in the data |
| air pressure | the amount that air pushes or presses on anything |
| low-pressure area | a place where warm air rises and pushes down on the earth's surface with less pressure |
| high-pressure area | a place where cool air sinks and pushes down on the earth's surface with more pressure |
| barometer | a tool that measures air pressure |
| wind vane | a tool that shows wind direction |
| anemometer | a tool that measures wind speed |
| precipitation | moisture that falls from the clouds to the ground |
| rain gauge | a tool that measures precipitation |
| humidity | amount of water vapor in the air |
| hygrometer | a tool that measures humidity |
| air mass | a large body of air that has about the same temperature and humidity |
| front | the line where two air masses meet |
| forecast | a prediction of what the weather will be like |
| meteorologist | a person who studies weather |
| National Weather Service | a government agency that collects information about the weather |
