Basic Meteorological Terms, Concepts, and Phenomena

July 25, 2011
Stormy Sunset

Taking in North Las Vegas at sunset

Clyde Swaim

Confused by weather forecasts? Here are some of the more common and basic meteorological terms, concepts, and phenomena. We hope this helps clear the clouds!

Anomaly: The deviation of (usually) temperature or precipitation in a given region over a specified period from the normal value for the same region.

Atmosphere: The mass of air surrounding the Earth and bound to it more or less permanently by the Earth's gravitational attraction.

Atmospheric Pressure (also called air pressure or barometric pressure): The pressure asserted by the mass of the column of air directly above any specific point. 

Aurora Borealis (also known as the northern lights): The luminous, radiant emission from the upper atmosphere over middle and high latitudes, and centered around the Earth's magnetic poles. These silent fireworks are often seen on clear winter nights in a variety of shapes and colors.

Barometer: A device for measuring atmospheric pressure.Blizzard of 1949

Blizzard: Includes winter storm conditions of sustained winds or frequent gusts of 35 mph or more that cause major blowing or drifting of snow, reducing visibility to less than one-quarter mile for 3 or more hours OR a typical Tuesday in New England during the wintertime.

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.

Climate: The prevalent long term weather conditions in a particular area. Climatic elements include precipitation, temperature, humidity, sunshine and wind velocity and phenomena such as fog, frost, and hail storms. Climate cannot be considered a satisfactory indicator of actual conditions since it is based upon a vast number of elements taken as an average.

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.

CycloneCyclone: 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.

Drought: Abnormally dry weather in a region over an extended period sufficient to cause a serious hydrological (water cycle) imbalance in the affected area. This can cause such problems as crop damage and water-supply shortage.

Flurries: Light snow falling for short durations. No accumulation or just a light dusting is all that is expected.

Fog: Water that has condensed close to ground level, producing a cloud of very small droplets that reduces visibility to less than one km (three thousand and three hundred feet).

Humidity: The amount of water vapor in the atmosphere.

Indian Summer: An unseasonably warm period near the middle of autumn, usually following a substantial period of cool weather. Learn more about Indian Summers here.

Jet Stream: Strong winds concentrated within a narrow band in the upper atmosphere. It normally refers to horizontal, high-altitude winds. The jet stream often “steers” surface features such as front and low pressure systems.

Tornado: A violent rotating column of air, in contact with the ground, pendant from a cumulonimbus cloud. A tornado does not require the visible presence of a funnel cloud. It has a typical width of tens to hundreds of meters and a lifespan of minutes to hours.

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.

Wind: Air in motion relative to the surface of the earth.

If you have questions about any other meteorological terms, please post below!


The National Oceanic and Atmospheric Administration (NOAA)


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The PDO cycle

28 days 13 months 364 days a year on a 33.3 year cycle 3 times. 99.9 years hot -cold -hot. Cold -hot -cold the sardine scales and anchovies scales prove the cycle in the oil core sample. The P.D.O. Shows this cycle. Maybe everyone should look at the nuclear dumping into the oceans by our governments and the cover up with bill Clinton and Julie Packard during the save the ocean campaign with the Global warming lie was started. If we measure tempiture with BTUs what we conceder cold is called super heat. True cold is -458? Degrees and we can't get to that temperature.(easily) groovin with nagari tube video will explain things


Why does the wind die down at night?

Dear Professor, Many's the

Dear Professor,

Many's the morning, just before the sun breaks above the horizon, a gentle breeze springs up to herald the start of a new day. Can you please tell me the meteorological term form this phenomenon?

Thank you in advance for this information.

D. L. Graham

If you live near the ocean or

The Editors's picture

If you live near the ocean or a large lake, a "sea breeze" or "onshore breeze" commonly occurs in the morning, as the land heats up more rapidly than the water. The hot air over land rises, the cool air over the water moves in to take its place, causing a breeze, due to the differences in pressure. The opposite is a "land breeze" or "offshore breeze" which flows from land to water in the evening, as the land cools down faster.