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| Weather | the day to day changes that occur in the atmosphere, meteorological day-to-day variations of the atmosphere and their effects on life and human activity. It includes temperature, pressure, humidity, clouds, wind, precipitation and fog. |
| Stratus | low altitude, flat sheets |
| Cumulus | big fluffy flat bottomed, A cloud in the shape of individual detached domes, with a flat base and a bulging upper portion resembling fluffy cauliflower. |
| Cirrus | high altitude, thin, small and whispy, High clouds, usually above 18,000 feet, composed of ice crystals and appearing in the form of white, delicate filaments or white or mostly white patches or narrow bands. |
| Nimbo/Nimbus | modifies cloud type indicating dark and rain |
| Climate | the long range predominant atmospheric conditions that are expected in a specific region of the Earth from year to year. |
| Calm | the absence of apparent motion in the air. |
| Circulation | The pattern of the movement of air. General circulation is the flow of air of large, semi-permanent weather systems, while secondary circulation is the flow of air of more temporary weather systems. |
| Eye | The low pressure center of a tropical cyclone. Winds are normally calm and sometimes the sky clears. |
| Lightning | Any form of visible electrical discharges produced by thunderstorms. |
| NOAA | National Oceanic and Atmospheric Administration. A branch of the U.S. Department of Commerce, NOAA is the parent organization of the National Weather Service. |
| Tornado Alley | The area of the United States in which tornadoes are most frequent. It encompasses the great lowland areas of the Mississippi, the Ohio, and lower Missouri River Valleys. Although no state is entirely free of tornadoes, they are most frequent in the Plains area between the Rocky Mountains and Appalachians |
| Air Mass | A large body of air that has similar horizontal temperature and moisture characteristics. |
| Cold Front | A narrow transition zone separating advancing colder air from retreating warmer air. The air behind a cold front is cooler and typically drier than the air it is replacing. |
| Depression | a region of low atmospheric pressure that is usually accompanied by low clouds and precipitation. |
| front | The boundary or transition zone between two different air masses. |
| high | An area of high pressure, usually accompanied by anticyclonic and outward wind flow resulting in good weather |
| low | - An area of low pressure, usually accompanied by cyclonic and inward wind flow resulting in bad weather. |
| Occluded Front | A complex frontal system that occurs when a cold front overtakes a warm front. Also known as an occlusion. |
| Stationary Front | a boundary between a warm front and a cold front where both fronts are temporarily not moving |
| warm front | A narrow transitions zone separating advancing warmer air from retreating cooler air. The air behind a warm front is warmer and typically more humid than the air it is replacing. |
| Blizzard | Includes winter storm conditions of sustained winds or frequent gusts of 35 mph or more that cause major blowing and drifting of snow, reducing visibility to less than one-quarter mile for 3 or more hours. |
| Cyclone | An area of low pressure around which winds blow counterclockwise in the Northern Hemisphere. Also the term used for a hurricane in the Indian Ocean and in the Western Pacific Ocean. |
| Funnel Cloud | A rotating, cone-shaped column of air extending downward from the base of a thunderstorm but not touching the ground. When it reaches the ground it is called a tornado. |
| Hurricane | A severe tropical cyclone with sustained winds over 74 mph (64 knots). Normally applied to such storms in the Atlantic Basin and the Pacific Ocean east of the International Date Line. |
| Nor'easter | A low-pressure disturbance forming along the South Atlantic coast and moving northeast along the Middle Atlantic and New England coasts to the Atlantic Provinces of Canada. It usually causes strong northeast winds with rain or snow. |
| Severe Thunderstorm | A strong thunderstorm with wind gusts in excess of 58 mph (50 knots) and/or hail with a diameter of 3/4" or more. |
| Thunderstorm | A storm with lightning and thunder, produced by a cumulonimbus cloud, usually producing gusty winds, heavy rain and sometimes hail. |
| Tornado | A rotating, cone-shaped column of air extending downward from the base of a thunderstorm reaching the ground |
| Tropical Disturbance | An organized mass of thunderstorms in the tropics than lasts for more than 24 hours, has a slight cyclonic circulation, and winds less than 23 mph. |
| Twister | A colloquial term for a tornado. |
| Millimeters of Mercury or Millibars | the units used to measure atmospheric pressure |
| Meteorologista | person who studies weather and climate. |
| Amospheric Pressure | (also called air pressure or barometric pressure) The pressure asserted by the mass of the column of air above earth |
| wind | air in motion relative to the surface of the earth. |
| Precipitation | liquid or solid water that falls from the atmosphere and reaches the ground. |
| Relative Humidity | the amount of water vapor in the air, compared to the amount the air could hold if it was totally saturated. (Expressed as a percentage). |
| humidity | the amount of water vapor in the atmosphere. |
| Barometer | an instrument for measuring atmospheric pressure. |
| Circulation | the pattern of the movement of air. |
| Hydrosphere | The total water of the Earth, comprising all bodies of water, ice, and water vapor in the atmosphere. |
| Sling Psychrometer | The total water of the Earth comprising all bodies of water, ice, and water vapor in the atomsphere |
| Saturation | a condition of the atmosphere in which a certain volume of air holds the maximum water vapor it can hold at a specific temperature. |
| Isobars | The lines that enclose areas of equal barometric pressure |
| When atmospheric pressure is greater than 1 atmosphere (1013mb or 760 mmHg) it is considered high pressure and will usually lead to good weather. | high, good |
