| A | B |
|---|
| weather | the behavior of the atmosphere - wind, temperature, pressure, precipitation - at a particular place and time |
| humidity | the amount of water vapor held in the air |
| relative humidity | the measure of the amount of water vapor in the air, compared to the maximum it can hold at a specific temperature; it varies with temperature and is between zero percent and 100 percent. |
| saturated | condition when air contains as much moisture as possible at a specific temperature |
| dew point | the temperature at which air is saturated with water and condensation begins |
| fog | a stratus cloud that forms on or near the ground when air is cooled to its dew point and condenses |
| precipitation | water or ice that condenses in the air and falls to the ground as rain, snow, sleet, or hail, depending on the air temperature |
| air mass | a large body of air that has the same properties as the surface over which it was formed |
| front | in weather systems, the boundary between two air masses |
| tornado | a violent, whirling, funnel-shaped wind storm, up to 500 km/hour, that moves in a narrow path over land |
| hurricane | a large, swirling, low-pressure system that forms over tropical oceans; winds must reach at least 120km/hr |
| meteorologist | a scientist who studies weather condtions using radar, satellites, and other instruments to make weather maps and forecasts |
| station model | in weather forecasting, a group of meteorological symbols on a weather map that depict weather information at one specific location |
| isotherm | on a weather map, a line connecting points of equal temperature |
| isobar | on a weather map, a line connecting points of equal atmospheric pressure |
| cloud seeding | the addition of silver iodide or dry ice particles to clouds to produce a change in weather conditions |
