| A | B |
|---|
| air mass | a huge body of air that has similar temperature, humidity, and air pressure throughout |
| tropical air mass | air mass that forms in the tropics |
| maritime air mass | air mass that forms over oceans |
| polar air mass | air mass that forms north 500 north latitutde or south of 500 south latitude |
| a front | the area where air masses meet and do not mix |
| continental air mass | air mass that forms over land, in the middle of continents |
| occluded air mass | a warm air mass that is cut off from the ground by cool air beneath it |
| cyclone | a swirling center of low air pressure |
| anticyclone | high pressure centers of dry air |
| storm | a violent disturbance in the atmosphere |
| lightning | a sudden spark, or energy discharge, between parts of a cloud or between the cloud and the ground |
| tornado | a rapidly whirling, funnel-shape cloud that reaches down from a storm cloud to touch Earth's surface |
| hurricane | a tropical storm that has winds of 119 kilometers per hour or higher |
| storm surge | a "dome" of water that sweeps across the coast where a hurricane lands |
| evacuate | people move away temporarily from a storm, fire, etc. |
| flash flood | a sudden, violent flood that occurs within a few hours, or even minutes, of a storm |
| meteorologist | scientist who study the causes of weather and try to predict it |
| El Nino | a warm-water event that occurs in the tropical Paciific Ocean periodically |
| Isobars | lines joining places on a weather map that have the same air pressure |
| Isotherms | lines joining places on a weather map that have the same temperature |
