| A | B |
|---|
| Air mass | a large volume of air with nearly the same temperature and humidity at different locations at the same altitude |
| Front | the boundary between two air masses |
| High Pressure System | a large weather system that surrounds a center of high pressure |
| Low Pressure System | a large weather system that surrounds a center of low pressure |
| Tropical Storm | a low-pressure system that starts near the equator and has winds that blow 65 kilometers per hour |
| Hurricane | a tropical low-pressure system with winds blowing at speeds of 120 kilometers per hour or more |
| Storm Surge | huge mass of ocean water produced by a hurricane |
| Blizzard | a blinding snowstorm with winds at least 56 km per hour and low temperatures |
| Thunderstorm | a storm with thunder and lightning |
| Tornado | a violently rotating column of air stretching from a cloud to the ground |
| Meteorologist | a scientist who studies weather |
| Isobar | a line on a surface weather map that connects places with the same air pressure |
| air pressure | The weight of air pressing down on an area |
| Precipitation | The process by which water returns to the earth's surface in the form of rain, snow, etc. |
| Evaporation | The process in which liquid water changes into a gas or water vapor |
| Condensation | The process by which water vapor changes back to a liquid |
| Barometer | The instrument used to measure air pressure |
| Anemometer | An instrument that includes three or four spinning, cone-shaped cups and is used to measure the speed of the wind |
| El Nino 1 | Trade winds completely change directions |
| El Nino 2 | There is a build up of warm water off the coast of South America. |
