The following outline is provided as ''an overview of and topical guide to'' the field of

Meteorology Meteorology is a branch of the atmospheric sciences (which include atmospheric chemistry and physics) with a major focus on weather forecasting. The study of meteorology dates back millennia, though significant progress in meteorology did no ...

. ; Meteorology : The interdisciplinary, scientific study of the Earth's atmosphere with the primary focus being to understand, explain, and forecast weather events. Meteorology, is applied to and employed by a wide variety of diverse fields, including the military, energy production, transport, agriculture, and construction.

Essence of meteorology

Climate Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologi ...

– the average and variations of weather in a region over long periods of time. *

– the interdisciplinary scientific study of the atmosphere that focuses on weather processes and

forecasting Forecasting is the process of making predictions based on past and present data. Later these can be compared (resolved) against what happens. For example, a company might estimate their revenue in the next year, then compare it against the actual ...

(in contrast with

climatology Climatology (from Greek , ''klima'', "place, zone"; and , ''-logia'') or climate science is the scientific study of Earth's climate, typically defined as weather conditions averaged over a period of at least 30 years. This modern field of study ...

). *

Weather Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloud cover, cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmos ...

– the set of all the phenomena in a given atmosphere at a given time.

Branches of meteorology

Microscale meteorology Microscale meteorology or micrometeorology is the study of short-lived atmospheric phenomena smaller than mesoscale, about or less. These two branches of meteorology are sometimes grouped together as "mesoscale and microscale meteorology" (MMM) ...

– the study of atmospheric phenomena about 1 km or less, smaller than mesoscale, including small and generally fleeting cloud "puffs" and other small cloud features *

Mesoscale meteorology Mesoscale meteorology is the study of weather systems smaller than synoptic scale systems but larger than microscale and storm-scale cumulus systems. Horizontal dimensions generally range from around 5 kilometers to several hundred kilometers. Ex ...

– the study of weather systems about 5 kilometers to several hundred kilometers, smaller than synoptic scale systems but larger than microscale and storm-scale cumulus systems, skjjoch as sea breezes, squall lines, and mesoscale convective complexes * Synoptic scale meteorology – is a horizontal length scale of the order of 1000 kilometres (about 620 miles) or more

Methods in meteorology

* Surface weather analysis – a special type of weather map that provides a view of weather elements over a geographical area at a specified time based on information from ground-based weather stations

Weather forecasting

Weather forecasting Weather forecasting is the application of science and technology to predict the conditions of the atmosphere for a given location and time. People have attempted to predict the weather informally for millennia and formally since the 19th cent ...

– the application of science and technology to predict the state of the atmosphere for a future time and a given location

Data collection

* Pilot Reports

Weather maps

Weather map A weather map, also known as synoptic weather chart, displays various meteorological features across a particular area at a particular point in time and has various symbols which all have specific meanings. Such maps have been in use since the m ...

* Surface weather analysis

Forecasts and reporting of

Atmospheric pressure Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars, ...

Dew point The dew point is the temperature to which air must be cooled to become saturated with water vapor, assuming constant air pressure and water content. When cooled below the dew point, moisture capacity is reduced and airborne water vapor will cond ...

High-pressure area A high-pressure area, high, or anticyclone, is an area near the surface of a planet where the atmospheric pressure is greater than the pressure in the surrounding regions. Highs are middle-scale meteorological features that result from interpl ...

Ice Ice is water frozen into a solid state, typically forming at or below temperatures of 0 degrees Celsius or Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaqu ...

Black ice Black ice, sometimes called clear ice, is a thin coating of glaze ice on a surface, especially on streets. The ice itself is not black, but visually transparent, allowing the often black road below to be seen through it. The typically low level ...

** Frost *

Low-pressure area In meteorology, a low-pressure area, low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. Low-pressure areas are commonly associated with inclement weather (such as cloudy, windy, with possible ...

Precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. ...

Temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measurement, measured with a thermometer. Thermometers are calibrated in various Conversion of units of temperature, temp ...

Weather front A weather front is a boundary separating air masses for which several characteristics differ, such as air density, wind, temperature, and humidity. Disturbed and unstable weather due to these differences often arises along the boundary. For in ...

* Wind chill *

Wind direction Wind direction is generally reported by the direction from which it originates. For example, a ''north'' or ''northerly'' wind blows from the north to the south. The exceptions are onshore winds (blowing onto the shore from the water) and offsho ...

Wind speed In meteorology, wind speed, or wind flow speed, is a fundamental atmospheric quantity caused by air moving from high to low pressure, usually due to changes in temperature. Wind speed is now commonly measured with an anemometer. Wind speed ...

Instruments and equipment of meteorology

Anemometer In meteorology, an anemometer () is a device that measures wind speed and direction. It is a common instrument used in weather stations. The earliest known description of an anemometer was by Italian architect and author Leon Battista Alberti ...

– a device for measuring wind speed; used in weather stations *

Barograph A barograph is a barometer that records the barometric pressure over time in graphical form. This instrument is also used to make a continuous recording of atmospheric pressure. The pressure-sensitive element, a partially evacuated metal cylinde ...

– an aneroid barometer that records the barometric pressure over time and produces a paper or foil chart called a barogram *

Barometer A barometer is a scientific instrument that is used to measure air pressure in a certain environment. Pressure tendency can forecast short term changes in the weather. Many measurements of air pressure are used within surface weather analysis ...

– an instrument used to measure atmospheric pressure using either water, air, or mercury; useful for forecasting short term changes in the weather *

Ceiling balloon A ceiling balloon also called a pilot balloon or pibal, is used by meteorologists to determine the height of the base of clouds above ground level during daylight hours. In the past, and sometimes today, a theodolite was used to track the ball ...

– a balloon, with a known ascent rate, used to measure the height of the base of clouds during daylight *

Ceiling projector The ceiling projector or cloud searchlight is used to measure the height of the base of clouds (called the ceiling) above the ground. It is used in conjunction with an alidade, usually positioned 1000 ft (300 m) away and wherever pos ...

– a device that is used, in conjunction with an alidade, to measure the height of the base of clouds * Ceilometer – a device that uses a laser or other light source to measure the height of the base of clouds. * Dark adaptor goggles – clear, red-tinted plastic goggles used either for adapting the eyes to dark prior to night observation or to help identify clouds during bright sunshine or glare from snow *

Disdrometer A disdrometer is an instrument used to measure the drop size distribution and velocity of falling hydrometeors. Some disdrometers can distinguish between rain, graupel, and hail. The uses for disdrometers are numerous. They can be used for ...

– an instrument used to measure the drop size, distribution, and velocity of falling hydrometeors *

Field mill Field Mill, currently known as One Call Stadium for sponsorship reasons, is a football ground in Mansfield, Nottinghamshire, England, and the home of Mansfield Town Football Club. It is the oldest ground in the Football League, hosting footb ...

– an instrument used to measure the strength of electric fields in the atmosphere near thunderstorm clouds *

Hygrometer A hair tension dial hygrometer with a nonlinear scale. A hygrometer is an instrument used to measure the amount of water vapor in air, in soil, or in confined spaces. Humidity measurement instruments usually rely on measurements of some other qu ...

– an instrument used to measure humidity * Ice Accretion Indicator – an L-shaped piece of aluminum 15 inches (38 cm) long by 2 inches (5 cm) wide used to indicate the formation of ice, frost, or the presence of freezing rain or freezing drizzle * Lidar (LIght raDAR) – an optical remote sensing technology used in atmospheric physics (among other fields) that measures the properties of scattered light to find information about a distant target *

Lightning detector A lightning detector is a device that detects lightning produced by thunderstorms. There are three primary types of detectors: ''ground-based'' systems using multiple antennas, ''mobile systems'' using a direction and a sense antenna in the same l ...

– a device, either ground-based, mobile, or space-based, that detects lightning produced by thunderstorms *

Nephelometer A nephelometer or aerosol photometer is an instrument for measuring the concentration of suspended particulates in a liquid or gas colloid. A nephelometer measures suspended particulates by employing a light beam (source beam) and a light dete ...

– an instrument used to measure suspended particulates in a liquid or gas colloid. Gas-phase nephelometers are used to provide information on atmospheric visibility and albedo *

Nephoscope A nephoscope is a 19th-century instrument for measuring the altitude, direction, and velocity of clouds, using transit-time measurement. This is different from a nephometer, which is an instrument used in measuring the amount of cloudiness. De ...

– an instrument for measuring the altitude, direction, and velocity of clouds *

Pyranometer A pyranometer is a type of actinometer used for measuring solar irradiance on a planar surface and it is designed to measure the solar radiation flux density (W/m2) from the hemisphere above within a wavelength range 0.3 μm to 3 μm. The name pyra ...

– A type of actinometer found in many meteorological stations used to measure broadband solar irradiance *

Radar Radar is a detection system that uses radio waves to determine the distance ('' ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, we ...

– see Weather radar *

Radiosonde A radiosonde is a battery-powered telemetry instrument carried into the atmosphere usually by a weather balloon that measures various atmospheric parameters and transmits them by radio to a ground receiver. Modern radiosondes measure or calcula ...

– an instrument used in weather balloons that measures various atmospheric parameters and transmits them to a fixed receiver *

Rain gauge A rain gauge (also known as udometer, pluvia metior, pluviometer, ombrometer, and hyetometer) is an instrument used by meteorologists and hydrologists to gather and measure the amount of liquid precipitation over a predefined area, over a period o ...

– an instrument that gathers and measures the amount of liquid precipitation over a set period of time *

Snow gauge A snow gauge is a type of instrument used by meteorologists and hydrologists to gather and measure the amount of solid precipitation (as opposed to liquid precipitation, which is measured by a rain gauge) over a set period of time. History The ...

– an instrument that gathers and measures the amount of solid precipitation over a set period of time * SODAR (SOnic Detection And Ranging) – an instrument that measures the scattering of sound waves by atmospheric turbulence * Solarimeter – a pyranometer, an instrument used to measure combined direct and diffuse solar radiation * Sounding rocket – an instrument-carrying sub-orbital rocket designed to take measurements and perform scientific experiments *

Stevenson screen A Stevenson screen or instrument shelter is a shelter or an enclosure to meteorological instruments against precipitation and direct heat radiation from outside sources, while still allowing air to circulate freely around them. It forms part of ...

– part of a standard weather station, it shields instruments from precipitation and direct heat radiation while still allowing air to circulate freely * Sunshine recorders – devices used to indicate the amount of sunshine at a given location * Thermograph – a chart recorder that measures and records both temperature and humidity *

Thermometer A thermometer is a device that measures temperature or a temperature gradient (the degree of hotness or coldness of an object). A thermometer has two important elements: (1) a temperature sensor (e.g. the bulb of a mercury-in-glass thermometer ...

– a device that measures temperature or temperature gradient * Weather balloon – a high-altitude balloon that carries instruments aloft and uses a radiosonde to send back information on atmospheric pressure, temperature, and humidity *

Weather radar Weather radar, also called weather surveillance radar (WSR) and Doppler weather radar, is a type of radar used to locate precipitation, calculate its motion, and estimate its type (rain, snow, hail etc.). Modern weather radars are mostly pulse- ...

– a type of radar used to locate precipitation, calculate its motion, estimate its type (rain, snow, hail, etc.) and forecast its future position and intensity *

Weather vane A wind vane, weather vane, or weathercock is an instrument used for showing the direction of the wind. It is typically used as an architectural ornament to the highest point of a building. The word ''vane'' comes from the Old English word , m ...

– a movable device attached to an elevated object such as a roof that shows the direction of the wind *

Windsock A windsock (also called a wind cone) is a conical textile tube that resembles a giant sock. It can be used as a basic indicator of wind speed and direction, or as decoration. They are typically used at airports to show the direction and strength ...

– a conical textile tube designed to indicate wind direction and relative wind speed *

Wind profiler A wind profiler is a type of weather observing equipment that uses radar or sound waves ( SODAR) to detect the wind speed and direction at various elevations above the ground. Readings are made at each kilometer above sea level, up to the extent o ...

– equipment that uses radar or SODAR to detect wind speed and direction at various elevations

History of meteorology

* History of weather forecasting – prior to the invention of meteorological instruments, weather analysis and prediction relied on pattern recognition, which was not always reliable *

History of surface weather analysis The history of surface weather analysis concerns the timetable of developments related to surface weather analysis. Initially a tool of study for the behavior of storms, surface weather analyses became a work in progress to explain current weathe ...

– initially used to study storm behavior, now used to explain current weather and as an aid in short term weather forecasting

Meteorological phenomena

– the pressure at any given point in the Earth's atmosphere *

Cloud In meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid droplets, frozen crystals, or other particles suspended in the atmosphere of a planetary body or similar space. Water or various other chemicals may ...

– a visible mass of droplets or frozen crystals floating in the atmosphere above the surface of a planet *

Rain Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water ...

– precipitation in which separate drops of water fall to the Earth from clouds, a product of the condensation of atmospheric water vapor *

Snow Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout ...

– precipitation in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds *

Freezing rain Freezing rain is rain maintained at temperatures below freezing by the ambient air mass that causes freezing on contact with surfaces. Unlike a mixture of rain and snow or ice pellets, freezing rain is made entirely of liquid droplets. The rain ...

– precipitation that falls from a cloud as snow, melts completely on its way down, then passes through a layer of below-freezing air becoming supercooled, at which point it will freeze upon impact with any object encountered * Sleet – term used in the United States and Canada for precipitation consisting of small, translucent ice balls, usually smaller than hailstones *

Tropical cyclone A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depen ...

– a storm system with a low-pressure center and numerous thunderstorms that produce strong winds and flooding rain * Extratropical cyclone – a low-pressure weather system occurring in the middle latitudes of the Earth having neither tropical nor polar characteristics *

– a boundary separating two masses of air of different densities; the principal cause of meteorological phenomena *

Low pressure In meteorology, a low-pressure area, low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. Low-pressure areas are commonly associated with inclement weather (such as cloudy, windy, with possible ...

– a region where the atmospheric pressure is lower in relation to the surrounding area *

Storm A storm is any disturbed state of the natural environment or the atmosphere of an astronomical body. It may be marked by significant disruptions to normal conditions such as strong wind, tornadoes, hail, thunder and lightning (a thunderstorm), ...

– any disturbed state of the atmosphere and strongly implying severe weather *

Flooding A flood is an overflow of water ( or rarely other fluids) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are an area of study of the discipline hydrolog ...

– an overflow of an expanse of water that submerges the land; a deluge *

Nor'easter A nor'easter (also northeaster; see below), or an East Coast low is a synoptic-scale extratropical cyclone in the western North Atlantic Ocean. The name derives from the direction of the winds that blow from the northeast. The original use ...

– a macro-scale storm along the East Coast of the United States, named for the winds that come from the northeast *

Wind Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few ho ...

– the flow of air or other gases that compose an atmosphere; caused by rising heated air and cooler air rushing in to occupy the vacated space. *

– a physical property that describes our common notions of hot and cold *

Invest (meteorology) An invest in meteorology (short for ''investigative area'', alternatively written INVEST) is a designated area of disturbed weather that is being monitored for potential tropical cyclone development. Invests are designated by three separate United ...

– An area with the potential for tropical cyclone development

Weather-related disasters

* Weather disasters *

Extreme weather Extreme weather or extreme climate events includes unexpected, unusual, severe, or unseasonal weather; weather at the extremes of the historical distribution—the range that has been seen in the past. Often, extreme events are based on a loca ...

* List of floods * List of natural disasters by death toll * List of severe weather phenomena

Leaders in meteorology

* William M. Gray (October 9, 1929 – April 16, 2016) – has been involved in forecasting hurricanes since 1984 * Francis Galton (February 16, 1822 - January 17, 1911) – was a polymath, and devised the first weather map, proposed a theory of anticyclones, and was the first to establish a complete record of short-term climatic phenomena on a European scale *

Herbert Saffir Herbert Seymour Saffir (29 March 1917 – 21 November 2007) () was an American civil engineer who co-developed (with meteorologist Robert Simpson) the Saffir–Simpson Hurricane Scale for measuring the intensity of hurricanes. As recently as ...

(March 29, 1917 – November 21, 2007) – was the developer of the Saffir-Simpson Hurricane Scale for measuring the intensity of hurricanes * Bob Simpson (November 19, 1912 – December 18, 2014) – was a meteorologist, hurricane specialist, first director of the National Hurricane Research Project, former director of the National Hurricane Center, and co-developer of the Saffir-Simpson Hurricane Scale.

External links

''See weather forecasting#External links for weather forecast sites''
Air Quality Meteorology
- Online course that introduces the basic concepts of meteorology and air quality necessary to understand meteorological computer models. Written at a bachelor's degree level.
The GLOBE Program
- (Global Learning and Observations to Benefit the Environment) An international environmental science and education program that links students, teachers, and the scientific research community in an effort to learn more about the environment through student data collection and observation.
Glossary of Meteorology
- From the American Meteorological Society, an excellent reference of nomenclature, equations, and concepts for the more advanced reader.
JetStream - An Online School for Weather
- National Weather Service
Learn About Meteorology
- Australian Bureau of Meteorology
The Weather Guide
- Weather Tutorials and News at About.com
Meteorology Education and Training (MetEd)
- The COMET Program
NOAA Central Library
- National Oceanic & Atmospheric Administration
The World Weather 2010 Project
The University of Illinois at Urbana-Champaign
Ogimet - online data from meteorological stations of the world, obtained through NOAA free servicesNational Center for Atmospheric Research Archives, documents the history of meteorologyWeather forecasting and Climate science
- United Kingdom Meteorological Office {{Outline footer