Meteorology and atmospheric science terminology · MLC-0110

Meteorology and atmospheric science terms: S (1,275)

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• SnowPrecipitation in the form of ice crystals, typically hexagonal in shape, that grow in the atmosphere and fall...
• Snow accumulationThe total depth of snow that has fallen and remained on a surface over a given period. This measurement...
• Snow accumulation and ablation modelIn hydrologic terms, a model which simulates snow pack accumulation, heat exchange at the air-snow interface...
• Snow advisoryThis product is issued by the National Weather Service when a low pressure system produces snow that may...
• Snow bannerA plume of snow blown off a mountain ridge or peak by strong winds, often appearing as a flag-like formation...
• Snow blindnessA temporary, painful eye condition caused by overexposure to ultraviolet (UV) radiation reflected off snow or...
• Snow blinkA bright, diffuse reflection of light from a snow-covered surface, visible in the sky above the horizon. This...
• Snow boardA flat, white-painted board, typically elevated slightly above the ground, used to measure the depth of new...
• Snow capA permanent covering of snow and ice found on the summit or upper slopes of a mountain or mountain range...
• Snow climateThe typical snowpack and avalanche conditions of a mountain range, averaged over many years. Snow climates...
• Snow cloudA cloud composed primarily of ice crystals and snowflakes, from which snow is falling or is expected to fall...
• Snow concreteSnow that has been compacted at low temperatures under a heavy object, such as a vehicle, and that then sets...
• Snow coreA sample of either freshly fallen snow, or the combined old and new snow on the ground. This is obtained by...
• Snow corniceA mass of snow or ice projecting over a mountain ridge.
• Snow courseA designated transect where manual measurements of snow depth and snow water equivalent are taken at regular...
• Snow coverThe extent and depth of snow and ice present on the Earth's surface. It is a dynamic feature that varies...
• Snow crustA hardened layer on or near the surface of a snowpack, formed by melting and refreezing, by wind packing of...
• Snow crystalAn individual ice crystal that forms in the atmosphere and grows by deposition of water vapor, often...
• Snow Data Assimilation SystemA physically based, mass conserving snow water equivalent (SWE) model.
• Snow dayA day on which schools, businesses, or other institutions are closed due to heavy snowfall or hazardous...
• Snow densityThe mass of snow per unit volume, typically expressed in kilograms per cubic meter or grams per cubic...
• Snow depthThe combined total depth of both the old and new snow on the ground.
• Snow droughtA period of significantly below-average snowpack accumulation, often characterized by reduced snow depth and...
• Snow eaterA colloquial name for a warm, dry wind that causes rapid melting and sublimation of snowpack, such as a Foehn...
• Snow fenceA barrier constructed to accumulate snowdrifts in desired locations, preventing them from obstructing roads...
• Snow flurries, see Snow flurry
• Snow flurryA brief, very light snow shower, intermittent and leaving little or no measurable accumulation on the ground...
• Snow forest climateKöppen's climate type for regions with a long, snowy winter, in which the coldest month averages minus 3...
• Snow gaugeAn instrument used to measure the depth of fallen snow or the water equivalent of snow. Simple snow gauges...
• Snow grainsPrecipitation consisting of very small, opaque, white ice particles that are flat or elongated. These solid...
• Snow iceA layer of ice formed on a body of water when a snow cover becomes saturated with water from below and...
• Snow lineThe elevation above which snow persists on the ground throughout the year, even during the warmest months...
• Snow matA device used to mark the surface between old and new snow. It is a square of white duck cloth about 28...
• Snow packSame as Snowcover; the combined layers of snow and ice on the ground at any one time.
• Snow patchAn isolated area of snow that persists on the ground after most of the surrounding snow cover has melted...
• Snow pelletsPrecipitation, usually of brief duration, consisting of crisp, white, opaque ice particles, round or conical...
• Snow pillowA device used to measure the water equivalent of a snowpack by weighing the snow that accumulates on its...
• Snow rollerA rare meteorological phenomenon where cylindrical masses of snow are formed by wind. These rollers occur...
• Snow shedA protective structure built over roads, railways, or other infrastructure in mountainous areas to prevent...
• Snow showerA snow shower is a short duration of moderate snowfall. Some accumulation is possible.
• Snow squallA snow squall is an intense, but limited duration, period of moderate to heavy snowfall, accompanied by...
• Snow stageThe last stage in the classical idealized ascent of a moist air parcel, which follows the dry, rain and hail...
• Snow stakeA graduated pole or rod installed vertically in the ground to measure the depth of accumulated snow...
• Snow stickA portable rod used to measure snow depth.
• Snow water equivalentThe water content obtained from melting accumulated snow.
• SnowboardA flat, solid, white material, such as painted plywood, approximately two feet square, which is laid on the...
• SnowbreakA structure or planting, such as a fence or row of trees, designed to reduce wind speed and control the...
• SnowcoverAlso known as Snow Pack; the combined layers of snow and ice on the ground at any one time.
• Snow-cover chartA map that depicts the geographical extent and depth of snow cover over a specific region or continent at a...
• SnowcreepThe slow, continuous downhill movement of a snowpack under its own weight, particularly on slopes, driven by...
• SnowdriftAn accumulation of snow shaped by wind, typically forming behind obstacles or in depressions where wind speed...
• Snowdrift glacierA small, stationary accumulation of snow and ice that persists through the summer melt season, formed by...
• Snowdrift iceIce formed when drifted snow is compacted, often by the wind, into a dense solid mass. It is found as slabs...
• SnowfallThe amount of new snow that falls over a specific period, measured as the vertical depth of freshly fallen...
• SnowfieldAn extensive area of perennial snow and ice that covers a relatively flat or gently sloping surface...
• SnowflakeAn individual ice crystal or an aggregate of multiple ice crystals that falls through the atmosphere. These...
• Snow-generating levelThe atmospheric layer within a cloud where ice crystals grow sufficiently large to fall as snow. This level...
• SnowmeltThe process by which snow and ice transform into liquid water, primarily due to rising air temperatures...
• Snowmelt floodA type of flood caused by the rapid melting of accumulated snow, often exacerbated by warm temperatures...
• Snowmelt floodingIn hydrologic terms, flooding caused primarily by the melting of snow.
• SnowpackThe accumulated layers of snow on the ground, formed from multiple snowfall events over a period. Its depth...
• Snowpack yieldThe amount of water released from a melting snowpack over a given period, often expressed as a volume or...
• SnowstormA meteorological event characterized by a continuous and substantial fall of snow over a period of hours or...
• SNRSignal-to-Noise Ratio
• SNW1. snow
• SNWFLSnowfall
• SodarA sonic detection and ranging system, an instrument that uses sound waves to measure wind speed and...
• SodiumA highly reactive alkali metal, chemical symbol Na, that exists in the atmosphere primarily as sodium...
• SOFAR technologyA method for underwater tracking and communication that uses the SOFAR (Sound Fixing and Ranging) channel...
• Soft radiationElectromagnetic or particle radiation with low energy and limited ability to penetrate matter. In atmospheric...
• Soft rimeA type of ice accretion that forms when supercooled water droplets freeze upon contact with a surface...
• Soft waterWater containing low concentrations of dissolved mineral ions, especially divalent cations like calcium and...
• SOIThe Southern Oscillation Index (SOI) has been developed to monitor the Southern Oscillation using the...
• Soil airThe gaseous phase within the pore spaces of soil, consisting primarily of nitrogen, oxygen, and carbon...
• Soil creepThe slow, continuous, downslope movement of soil and regolith under the influence of gravity. The movement is...
• Soil moistureThe amount of water held within the pore spaces of soil, representing a key component of the terrestrial...
• Soil moisture contentThe quantity of water present in a given volume or mass of soil, expressed as a percentage or fraction. This...
• Soil moisture deficitThe amount of water required to bring the soil moisture content up to its field capacity, representing the...
• Soil moisture profileThe vertical distribution of water content within the soil column from the surface down to a certain depth...
• Soil moisture tensionThe force per unit area that must be applied to extract water from the soil, also known as matric potential...
• Soil stripeA linear pattern of bare ground or vegetation that forms in periglacial environments due to frost heave and...
• Soil temperatureThe measurement of heat within the soil profile, recorded at specific, standardized depths below the surface...
• Soil thermographA self-recording instrument that continuously measures and records soil temperature over time. It typically...
• Soil zoneA distinct layer or horizon within the soil profile characterized by specific physical, chemical, and...
• Soil-water pressureThe force per unit area exerted by water within the pore spaces of soil, which can be either positive...
• Sol-air temperatureA theoretical outdoor air temperature that produces the same rate of heat transfer through a surface as the...
• SolanoA hot east to southeast wind of southern Spain, a local form of the sirocco that blows mainly from June to...
• Solar activityThe dynamic processes occurring on the Sun, including sunspots, solar flares, and coronal mass ejections...
• Solar angleThe angle at which the Sun's rays strike the Earth's surface at a given location and time. This angle varies...
• Solar atmospheric tidePeriodic oscillations in atmospheric pressure, temperature, and wind that are driven by the diurnal and...
• Solar aureoleA bright, whitish or yellowish ring of light immediately surrounding the Sun, caused by the forward...
• Solar Backscatter Ultraviolet RadiometerAn instrument designed to measure the Earth's atmospheric ozone concentration by detecting backscattered...
• Solar climateThe climate of a region determined solely by the amount of solar radiation received at its surface, without...
• Solar coordinatesIn solar-terrestrial terms, Central Meridian Distance (CMD). The angular distance in solar longitude measured...
• Solar cycleA periodic variation in the Sun's activity, characterized by changes in the number of sunspots, solar flares...
• Solar dayThe time interval between two successive transits of the Sun across the local meridian. This period...
• Solar fluxThe rate at which solar electromagnetic radiation arrives per unit area at a given distance from the Sun...
• Solar Imaging SuiteThe group of solar instruments planned for the GOES-R series of weather satellites to monitor solar activity...
• Solar infraredThe portion of the electromagnetic spectrum emitted by the sun that falls within the infrared range...
• Solar maximumIn solar-terrestrial terms, the month(s) during the solar cycle when the 12-month mean of monthly average...
• Solar minimumIn solar-terrestrial terms, the month(s) during the solar cycle when the 12-month mean of monthly average...
• Solar noonThe time of day at which the sun is the highest in the sky. This time varies through the year due to the...
• Solar proton eventAn eruption from the Sun that releases high-energy protons and other charged particles into space, often...
• Solar radiationThe electromagnetic radiation emitted by the Sun, encompassing wavelengths from gamma rays to radio waves...
• Solar radio emissionRadio waves generated by processes in the Sun's atmosphere, including thermal emission from the quiet Sun and...
• Solar Sector BoundaryIn solar-terrestrial terms, the apparent solar origin, or base, of the interplanetary sector boundary marked...
• Solar spectrumThe distribution of electromagnetic radiation emitted by the Sun, ranging from gamma rays to radio waves. It...
• Solar tideThe tide produced by the Sun, as distinct from the lunar tide. In the ocean it comes from the Sun's...
• Solar windA continuous stream of charged particles, primarily electrons and protons, ejected from the Sun's upper...
• Solar X-ray ImagerA specialized instrument designed to observe the Sun's corona and solar flares in X-ray wavelengths. It...
• Solar zenith angleThe angular distance between the sun's position in the sky and the local zenith, which is the point directly...
• SolarimeterAn instrument that measures the total flux of solar radiation received from the entire hemisphere above the...
• Solar-topographic theoryA hypothesis on the cause of the Pleistocene glaciations, put forward by the Yale geologist Richard Foster...
• SolenoidA tube formed in a baroclinic fluid where equally spaced isobaric surfaces intersect equally spaced isosteric...
• SolenoidalDescribing a vector field whose divergence is zero, meaning that the net flux of the field through any closed...
• Solenoidal indexA measure of baroclinicity in a vertical cross-section of the atmosphere, given by the poleward gradient of...
• Solid rotationA type of rotation where all parts of a fluid or body rotate together as a rigid unit, meaning the angular...
• SolifluctionThe slow flow of water-saturated soil and regolith down a slope, especially in periglacial environments where...
• Solitary waveA self-reinforcing wave packet that maintains its shape while propagating at a constant velocity, often...
• SolitonA self-reinforcing solitary wave that maintains its shape and speed as it propagates, even after interacting...
• SOLNSolution
• SOLNSsolutions
• SolsticeEither of the two points in the Earth's orbit when the Sun reaches its highest or lowest apparent position in...
• SolubilityThe maximum concentration of a substance that can dissolve in a solvent at a given temperature and pressure...
• Somali CurrentA western boundary current in the Indian Ocean that flows northward along the coast of Somalia during the...
• Somali jetA strong, narrow low-level airflow of the Northern Hemisphere summer monsoon that crosses the equator along...
• Sonic anemometerAn instrument that measures wind speed and direction by detecting the time it takes for ultrasonic sound...
• Sonic thermometerA device that determines air temperature by measuring the speed of sound through a specific path in the...
• Sonora weatherA local name in coastal Southern California for summer spells of hot, humid, muggy weather, produced when...
• SOOScience and Operations Officer
• SootFine black particulate matter, mostly carbon with tarry organic compounds, formed by incomplete combustion of...
• Sorbtion nucleusAn aerosol particle on which ice forms directly from water vapor by deposition, the vapor being taken up on...
• SorocheAcute mountain sickness, a physiological response experienced by individuals ascending rapidly to high...
• SorptionA physical or chemical process where one substance becomes attached to another, encompassing both absorption...
• Sou'easterA wind that blows from the southeast, or a gale or storm in which southeast winds prevail. Sou'easter is the...
• SoundA mechanical wave that propagates through a medium, such as air, by means of oscillations in pressure or...
• Sound channelA layer in the atmosphere or ocean where sound waves are refracted and confined, allowing them to travel long...
• Sound pressure levelA logarithmic measure of the effective pressure of a sound relative to a standard reference value. It is...
• Sound waveA longitudinal wave of alternating compression and rarefaction in which particles of a medium oscillate...
• SounderAn instrument carried on satellites, aircraft, or balloons that measures atmospheric properties at multiple...
• SoundingA set of measurements of atmospheric conditions taken at multiple vertical levels above a specific location...
• Sounding balloonA balloon, typically filled with hydrogen or helium, that carries a radiosonde or other meteorological...
• Sounding poleA graduated rod used for manually measuring the depth of water in a river, lake, or reservoir, or the depth...
• Sounding weightA heavy, streamlined lead or brass weight attached to the end of a sounding line or wire used to measure...
• SourceA location, area, or process that releases a substance, such as a pollutant or greenhouse gas, into the...
• Source regionA large, relatively homogeneous geographical area where air masses acquire their characteristic temperature...
• Source termsMathematical expressions within atmospheric models that represent the generation or removal of atmospheric...
• South Atlantic convergence zoneA persistent band of cloudiness and precipitation that extends southeastward from the Amazon Basin across the...
• South Atlantic CurrentAn eastward-flowing ocean current that forms the southern limb of the subtropical South Atlantic Gyre...
• South Atlantic highA large, semi-permanent subtropical anticyclone over the South Atlantic Ocean, also called the St. Helena...
• South Equatorial CountercurrentAn eastward-flowing current of the tropical Pacific and Atlantic that lies south of the equator, between...
• South Equatorial CurrentA broad westward-flowing ocean current of the tropical Pacific, Atlantic and Indian Oceans, driven directly...
• South foehnA warm, dry, and often gusty wind that descends the leeward side of a mountain range, specifically when the...
• South Indian Ocean CurrentA broad, eastward-flowing ocean current located in the southern Indian Ocean, generally between 30°S and 40°S...
• South Java CurrentA coastal ocean current along the southern coast of Java in the eastern Indian Ocean whose direction follows...
• South Pacific convergence zoneA persistent band of atmospheric convection and rainfall that extends from the western Pacific warm pool...
• South Pacific CurrentA cold, broad, slow-moving ocean current that flows eastward across the South Pacific Ocean between...
• Southeast tradesPersistent winds that blow from the southeast in the Southern Hemisphere tropical and subtropical regions...
• SoutheasterA wind that blows from the southeast, or a storm characterized by such winds. In the Southern Hemisphere...
• SoutherA strong wind or gale that blows from the south, often bringing a sudden drop in temperature and stormy...
• Southern OscillationA large-scale atmospheric pressure seesaw between the tropical eastern and western Pacific Ocean. It is...
• Southern Oscillation indexA standardized index that measures the strength and phase of the Southern Oscillation, a large-scale...
• Southwest monsoonA seasonal wind system that brings heavy rainfall to South Asia and Southeast Asia during the summer months...
• Southwest Monsoon CurrentA strong, eastward-flowing ocean current in the northern Indian Ocean that develops during the boreal summer...
• SouthwesterA wind that blows from the southwest, or a gale characterized by such winds. In the mid-latitudes of the...
• SOxA group of sulfur and oxygen compounds, primarily sulfur dioxide (SO2) and sulfur trioxide (SO3), that are...
• Space chargeAn accumulation of electric charge within a volume of space, rather than on a surface. In the atmosphere...
• Space Environment Center(SEC) - This center provides real-time monitoring and forecasting of solar and geophysical events, conducts...
• Space Environment In-Situ SuiteA set of four sensors on the GOES-R series of geostationary satellites designed to monitor space weather...
• Space Environmental MonitorAn instrument or system used to observe and measure conditions in the space environment, including radiation...
• Space weatherThe conditions in space that can affect Earth and its technological systems, primarily driven by solar...
• Spark dischargeA sudden, luminous electrical discharge that occurs when the electric field strength in a gas exceeds its...
• Spatial averageA statistical measure that represents the average value of a variable over a defined geographical area or...
• Spatial dendriteA snow crystal whose branching arms spread through several planes instead of one, giving a three-dimensional...
• SPCStorm Prediction Center
• SPCLYEspecially
• SPD1) Speed
• Spearhead echoA radar echo associated with a downburst with a pointed appendage extending toward the direction of the echo...
• SPECIA special meteorological report issued when weather conditions at an airport change rapidly or meet specific...
• Special avalanche warningIssued by the National Weather Service when avalanches are imminent or occurring in the mountains. It is...
• Special fire weatherMeteorological services uniquely required by user agencies which cannot be provided at an NWS office during...
• Special marine warning(SMW) A warning product issued for potentially hazardous weather conditions usually of short duration (up to...
• Special observationA meteorological measurement or set of measurements taken outside of routine operational schedules or...
• Special Sensor Microwave ImagerA seven-channel passive microwave radiometer flown on Defense Meteorological Satellite Program satellites...
• Special Sensor Microwave TemperatureA satellite-borne passive microwave radiometer designed to measure atmospheric temperature profiles from the...
• Special tropical disturbance statementThis statement issued by the National Hurricane Center furnishes information on strong and formative...
• Special weather reportAn unscheduled aviation weather report issued when meteorological conditions at an airport change and cross...
• Special weather statementsAdvisories issued by meteorological services to inform the public about weather conditions that are...
• Specific conductanceA measure of the ability of water to conduct an electrical current, which is directly related to the...
• Specific dischargeThe volume flow rate of water through a unit cross-sectional area of a porous medium, such as soil or an...
• Specific energyThe total energy per unit mass of a fluid parcel, encompassing its internal energy, kinetic energy, and...
• Specific gravityThe ratio of the density of any substance to the density of water.
• Specific heat capacityThe amount of heat energy required to raise the temperature of one unit mass of a substance by one degree...
• Specific humidityThe ratio of the mass of water vapor to the total mass of moist air in a given volume. It is a measure of the...
• Specific retentionThe volume of water that a given volume of porous medium, such as soil or rock, can retain against the force...
• Specific storageThe volume of water released from or taken into storage by a unit volume of a porous aquifer material per...
• Specific volumeThe volume occupied by a unit mass of a substance, representing the reciprocal of its density. In...
• Specific yieldThe volume of water that drains by gravity from a saturated porous medium, such as an aquifer, divided by the...
• Specific-volume anomalyThe difference between the specific volume of a parcel of seawater at a given temperature, salinity, and...
• Spectral densityA measure of how the power or variance of a time series is distributed over different frequencies. It...
• Spectral diffusivityA turbulent diffusivity expressed as a function of wavenumber instead of a single constant, so that eddies of...
• Spectral functionA mathematical function that describes the distribution of a physical quantity, such as energy or intensity...
• Spectral gapA minimum in the energy spectrum of atmospheric winds, found at periods from roughly ten minutes to a couple...
• Spectral hygrometerAn instrument that determines the amount of water vapor in the atmosphere by measuring the absorption of...
• Spectral intervalA defined range of wavelengths or frequencies within the electromagnetic spectrum. In meteorology...
• Spectral irradianceThe radiant flux incident on a surface per unit area, per unit wavelength or frequency interval. It describes...
• Spectral lineA distinct dark or bright line in an otherwise continuous spectrum, caused by the absorption or emission of...
• Spectral methodA numerical technique used to solve partial differential equations by representing the unknown functions as a...
• Spectral modelA type of numerical weather prediction model that represents atmospheric variables as a sum of basis...
• Spectral numerical analysisA mathematical technique used in atmospheric science to analyze and solve differential equations by...
• Spectral numerical predictionThe forecasting of atmospheric conditions using numerical models that represent atmospheric variables in...
• Spectral radianceThe radiant power emitted, reflected, transmitted, or received by a surface per unit projected area per unit...
• Spectral similarityThe degree to which the spectral characteristics, such as absorption or emission patterns, of two different...
• Spectral transform modelA type of numerical weather prediction model that uses spectral methods for horizontal representation of...
• Spectral wave densityOn a buoy report, energy in (meter*meter)/Hz, for each frequency bin (typically from 0.03 Hz to 0.40 Hz).
• Spectral wave directionOn a buoy report, mean wave direction, in degrees from true North, for each frequency bin.
• SpectrobolometerAn instrument designed to measure the distribution of radiant energy across different wavelengths within a...
• SpectrographAn optical instrument designed to separate incident electromagnetic radiation into its constituent...
• SpectroheliographAn instrument that produces photographic or digital images of the Sun at a single, very narrow band of...
• SpectrometerAn instrument that measures the intensity of electromagnetic radiation as a function of its wavelength or...
• SpectrophotometerAn instrument that measures the intensity of light as a function of wavelength, specifically quantifying the...
• SpectropyrheliometerAn instrument designed to measure the spectral distribution of direct solar irradiance. It combines the...
• SpectroscopeAn optical instrument used to separate light into its component wavelengths, allowing for visual observation...
• SpectroscopyThe study of the interaction between matter and electromagnetic radiation as a function of wavelength or...
• SpectrumThe distribution of a physical quantity's magnitude or energy across a range of frequencies, wavelengths...
• Spectrum widthThis WSR-88D radar product depicts a full 360 degree sweep of spectrum width data indicating a measure of...
• Spectrum width cross sectionThis WSR-88D radar product displays a vertical cross section of spectrum width on a grid with heights up to...
• Specular reflectionThe reflection of light or other waves from a smooth surface, where the angle of incidence equals the angle...
• Specular reflectorA surface that reflects incident radiation in a single, well-defined direction, where the angle of reflection...
• Speed of lightThe constant speed at which all electromagnetic radiation, including visible light, propagates through a...
• Speed of soundThe velocity at which a sound wave propagates through an elastic medium. In the Earth's atmosphere, this...
• Speed shearThe component of wind shear which is due to a change in wind speed with height, e.g., southwesterly winds of...
• Speed-up heightThe height above the ground, usually taken at a hill crest, at which the fractional speed-up of the wind...
• Speed-up ratioA dimensionless quantity representing the ratio of the wind speed at a specific location, often over a...
• Speed-up windThe phenomenon where wind accelerates as it flows over or around topographic features like hills, ridges, or...
• SPENESNESDIS Satellite Precipitation Estimates
• Sphere calibrationReflectivity calibration of a radar by pointing the dish at a metal sphere of (theoretically) known...
• Spherical albedoThe fraction of incident solar radiation that is reflected by a celestial body, integrated over all...
• Spherical coordinatesA three-dimensional coordinate system that defines a point in space using its distance from the origin...
• Spherical harmonicA class of mathematical functions used to represent a function defined over the surface of a sphere...
• Spherical pyranometerA type of pyranometer designed to measure global solar radiation incident from all directions onto a...
• Spherical pyrgeometerAn instrument that measures longwave (terrestrial infrared) radiation arriving from all directions, the full...
• Spherical pyrradiometerAn instrument that measures the total radiation, shortwave plus longwave, arriving from all directions onto a...
• Spherical shell apparatusA laboratory device consisting of two concentric spheres with the space between them filled with fluid, used...
• Spherical symmetryA property of a system where its physical characteristics are uniform in all directions from a central point...
• Spherical waveA wave whose wavefronts are concentric spheres expanding or contracting from a central point source. The...
• SpiculeA dynamic, narrow jet of plasma that shoots upward from the Sun's chromosphere into the lower corona. These...
• Spider lightningA type of lightning discharge that propagates horizontally for long distances, often appearing as a luminous...
• SpilloverThe part of orographic precipitation that falls a short distance downwind of a mountain ridge, because the...
• SpillwayIn hydrologic terms, a structure over or through which excess or flood flows are discharged. If the flow is...
• Spillway crestIn hydrologic terms, the elevation of the highest point of a spillway.
• Spillway design floodThe maximum flood flow, expressed as a hydrograph, that a dam's spillway is designed to safely pass without...
• Spindown timeThe characteristic time scale over which a rotating fluid system, such as an atmospheric vortex or a...
• Spinning Enhanced Visible and Infrared ImagerA radiometer carried aboard Meteosat Second Generation (MSG) geostationary satellites, designed to observe...
• Spin-scan cloud cameraA type of imaging instrument used on early geostationary meteorological satellites to capture images of...
• Spin-UpSlang for a small-scale vortex initiation, such as what may be seen when a gustnado, landspout, or suction...
• Spinup timeThe period required for a numerical weather prediction model or a rotating fluid system to reach a state of...
• Spiral scanningA method of data acquisition used by some meteorological radars where the antenna rotates continuously while...
• Spirit thermometerA type of liquid-in-glass thermometer that uses a sealed glass tube containing a colored alcohol, such as...
• SpissatusA species of cirrus cloud characterized by a dense, opaque appearance that can obscure the sun or moon. These...
• SpitAn elongated, narrow ridge of sand or shingle that projects from the land into a body of water, such as a sea...
• SPKLSprinkle
• SplashThe dispersion of liquid droplets that occurs when a raindrop or other liquid impact a surface. In...
• Spline functionA mathematical function defined piecewise by polynomials, used for interpolating data points in...
• SplinteringA process of secondary ice production where freezing water droplets shatter upon collision with larger ice...
• Split cold frontA type of cold front where the main frontal boundary aloft becomes separated from the surface cold front...
• Split flowA flow pattern high in the atmosphere characterized by diverging winds. Storms moving along in this type of...
• Split windowA technique in satellite remote sensing that uses measurements from two adjacent infrared spectral channels...
• Split-explicit methodA numerical integration technique used in atmospheric models to efficiently solve prognostic equations by...
• Splitting convective stormA thunderstorm that divides into two distinct cells, a left-moving and a right-moving storm, as it...
• Splitting stormA thunderstorm which splits into two storms which follow diverging paths (a left mover and a right mover)...
• SPLNSSouthern Plains
• Spongy iceA mixture of ice and unfrozen liquid water in which an open framework of ice crystals holds water in its...
• Spontaneous nucleationThe process by which a new phase, such as ice crystals or cloud droplets, forms in a supersaturated or...
• Sporadic EIn solar-terrestrial terms, a phenomenon occurring in the E region of the ionosphere, which significantly...
• Sporadic E-layerAn unusual patch of high electron density that forms intermittently within the E region of the ionosphere...
• Spot windA measurement of wind velocity taken at a specific location and time, providing an instantaneous snapshot of...
• SPOTNILIn solar-terrestrial terms, a spotless disk.
• SpottingOutbreak of secondary fires as firebrands or other burning materials are carried ahead of the main fire line...
• SprayAn ensemble of water droplets torn by the wind from an extensive body of water, generally from the crests of...
• Spray electrificationThe process by which electric charges are generated and separated when water droplets or ice particles break...
• SPRDSpread
• SpreadThe difference between the dry-bulb temperature and the dew point temperature, indicating the amount of...
• Spread skill correlationA statistical measure used in ensemble forecasting to quantify the relationship between the forecast spread...
• spread-FA phenomenon observed in ionograms where the F-region echo appears as a diffuse, broadened trace rather than...
• SpringThe season of the year that follows winter and precedes summer, characterized by increasing daylight hours...
• Spring crustA hard, icy layer that forms on the surface of a snowpack during spring, resulting from repeated cycles of...
• Spring snowSnow that falls or persists during the spring season, characterized by its higher water content and tendency...
• Spring tideA tide that occurs when the gravitational forces of the sun and moon combine to produce the largest tidal...
• SprinkleA form of very light precipitation consisting of small, widely scattered water droplets. The drops are larger...
• SpriteA large-scale electrical discharge that occurs high above active thunderstorms, extending upwards into the...
• SPSSevere Weather Potential Statement
• SqThe symbol representing the solar quiet daily variation of the Earth's magnetic field, which is a regular...
• SQLNSquall Line
• SquallA sudden, strong increase in wind speed that lasts for several minutes, often accompanied by a shift in wind...
• Squall lineA narrow band of active thunderstorms that forms along or ahead of a cold front, characterized by a...
• Squall-line thunderstormA type of thunderstorm that is organized into a linear band, often associated with a cold front or other...
• SRF(Surf Zone Forecast) - A National Weather Service routine or event driven forecast product geared toward...
• SRHStorm-Relative Helicity
• SRNSouthern
• SSSandstorm
• S-scaleOne of the NOAA Space Weather Scales, rating solar radiation storms from S1 (minor) to S5 (extreme) by the...
• SSHSSaffir/Simpson Hurricane Scale
• SSTSea Surface Temperature
• STStratus
• St. Elmo's fireA continuous, luminous electrical discharge that appears as a faint glow or brush of light on pointed...
• St Lawrence freeze-up outlookA National Weather Service forecast product to keep mariners informed of the projected freeze-up date of ice...
• St. Luke's summerA period of unseasonably warm, dry, and calm weather that occurs in mid-autumn, typically around the feast...
• St. Martin's summerA period of unseasonably warm, dry, and calm weather that occurs in autumn, especially in parts of Europe...
• St. Swithin's DayA traditional weather lore day, observed on July 15th, which suggests that the weather pattern on this...
• StabilityThe resistance of an air parcel to vertical displacement, or its tendency to return to its original position...
• Stability categoriesA classification system used to describe the atmospheric conditions that influence the dispersion of...
• Stability chartA graphical representation used in meteorology to analyze the vertical temperature and moisture structure of...
• Stability indexA single number computed from the temperature and moisture of the lower atmosphere that summarizes its static...
• StableAn atmospheric state with warm air above cold air which inhibits the vertical movement of air.
• Stable airAtmospheric air that resists vertical motion, meaning that an air parcel displaced vertically will tend to...
• Stable air massA body of air in which a parcel of air, if displaced vertically, tends to return to its original position...
• Stable boundary layerThe lowest part of the atmosphere where vertical mixing is suppressed due to a temperature inversion, meaning...
• Stable corePost-sunrise, elevated remnant of the temperature inversion that has built up overnight within a valley.
• Stable motionThe characteristic of an atmospheric system or fluid parcel to return to its initial state or equilibrium...
• Stable oscillationA type of periodic motion in a system where, if disturbed, the amplitude of the oscillations remains bounded...
• Stable profileA vertical distribution of atmospheric temperature where the environmental lapse rate is less than the moist...
• Stable waveA type of atmospheric wave that, once generated, does not grow in amplitude but rather maintains its form or...
• Staccato lightningA Cloud to Ground (CG) lightning discharge which appears as a single very bright, short-duration stroke...
• Stack effectThe vertical movement of air within buildings or other structures, driven by differences in air density...
• Staff gaugeA simple, graduated scale or ruler permanently installed in a body of water, such as a river, lake, or...
• StageThe height of the water surface in a river, lake, or reservoir relative to an arbitrary or established datum...
• Stage-discharge relationThe empirical relationship between the water level (stage) and the volume of water flowing per unit time...
• Staggered gridA numerical discretization technique used in atmospheric models where different prognostic variables are...
• Stagnation areaA region in a fluid flow where the velocity of the fluid is significantly reduced or brought to a near...
• Stagnation pressureThe pressure that a fluid would attain if it were brought to rest isentropically (without heat transfer or...
• Stair steppingIn hydrologic terms, the process of continually updating river forecasts for the purpose of incorporating the...
• StandardA set of reference atmospheric conditions used for calibrating instruments, comparing data, and standardizing...
• Standard artillery atmosphereA fixed reference atmosphere adopted for computing artillery firing tables, giving temperature, pressure and...
• Standard artillery zoneOne of a fixed series of horizontal layers of the atmosphere, each defined by its altitude limits above the...
• Standard atmosphereA hypothetical model of the Earth's atmosphere that defines average vertical profiles of temperature...
• Standard atmospheric pressureThe average atmospheric pressure at mean sea level, defined as 1013.25 hectopascals (hPa) or 29.92 inches of...
• Standard densityThe density of air at standard atmospheric conditions, typically defined at mean sea level in the...
• Standard density altitudeThe altitude in the International Standard Atmosphere (ISA) at which the air density would be equal to the...
• Standard depthA pre-determined, internationally agreed-upon depth in a body of water at which oceanographic or limnological...
• Standard deviationA measure of the amount of variation or dispersion of a set of values. A low standard deviation indicates...
• Standard errorA measure of the statistical accuracy of an estimate, representing the standard deviation of the sampling...
• Standard gravityThe nominal acceleration of an object due to Earth's gravity, established by convention as a fixed value for...
• Standard isobaric surfaceA conceptual surface in the atmosphere characterized by a uniform value of atmospheric pressure...
• Standard precipitation indexA probability-based index used to monitor and characterize meteorological drought by measuring precipitation...
• Standard pressureA defined constant value representing the approximate average atmospheric pressure at mean sea level. This...
• Standard pressure altitudeThe altitude in the International Standard Atmosphere (ISA) corresponding to a given atmospheric pressure. It...
• Standard propagationThe typical behavior of radio waves in the atmosphere under average atmospheric conditions, where the...
• Standard synoptic timesThe times of 0000, 0600, 1200, and 1800 UTC. Also known as the main synoptic times.
• Standard temperatureA reference temperature value, typically defined as 15 degrees Celsius (59 degrees Fahrenheit) at mean sea...
• Standard time of observationThe internationally agreed-upon times at which meteorological observations are made and recorded at weather...
• Standardized variateA random variable that has been transformed to have a mean of zero and a standard deviation of one. This...
• Standing cloudA cloud formation that remains relatively stationary over a geographical location, even in the presence of...
• Standing waveAn oscillation pattern that remains in a constant position, created by the interference of two waves...
• Standpipe storage precipitation gaugeA type of non-recording precipitation gauge designed to collect and store rainfall over an extended period...
• Stanton numberA dimensionless number that quantifies the ratio of heat transfer to the thermal capacity of a fluid flow. It...
• Stark effectThe shift and splitting of atomic and molecular energy levels, and so of their spectral lines, caused by an...
• Starting plumeThe initial, transient phase of a buoyant plume's development, characterized by a distinct head or vortex...
• State forecast productThis National Weather Service product is intended to give a good general picture of what weather may be...
• State of groundA coded description in synoptic weather reports of the condition of the ground surface at an observing...
• State of the seaA description of the condition of the ocean surface, primarily referring to the height and characteristics of...
• State of the skyA meteorological observation that describes the amount of cloud cover and the general appearance of the sky...
• State variableA physical quantity that describes the macroscopic condition of a system at a given moment, independent of...
• State weather roundupThis is a National Weather Service tabular product which provides routine hourly observations within the...
• StaticAtmospheric electrical discharges that produce crackling or hissing sounds in radio receivers, often...
• Static energies, see Static energy
• Static energyThe sum of the internal energy and potential energy per unit mass of an air parcel, often expressed as the...
• Static instabilityA condition in the atmosphere where a vertically displaced air parcel continues to move in the direction of...
• Static levelThe level at which water stands in a well when it is not being pumped and is not influenced by recent...
• Static pressureThe pressure exerted by a fluid at rest, or the pressure measured by a sensor moving with the fluid such that...
• Static pressure portAn opening on an aircraft's fuselage designed to measure ambient atmospheric pressure, undisturbed by the...
• Static stabilityThe tendency of an air parcel to return to its original vertical position after being displaced. The...
• StationA fixed geographical location where meteorological observations are regularly collected and recorded. These...
• Station circleA symbolic representation on a weather map that indicates the location of a meteorological observing station...
• Station continuity chartA chart kept for a single observing station on which its successive observations, such as pressure...
• Station designatorA unique alphanumeric code assigned to a meteorological observing station for identification purposes. These...
• Station IDFive-digit WMO Station Identifier used by the Buoy Data Center since 1976. ID's can be reassigned to future...
• Station index numberA numerical identifier assigned to a meteorological observing station, typically by the World Meteorological...
• Station locationThe geographical position of a meteorological observing station, precisely defined by its latitude...
• Station modelA standardized plotting of observed weather conditions at a specific location, using a combination of symbols...
• Station pressureThe atmospheric pressure measured directly at the elevation of a meteorological observing station. This raw...
• Stationary eddiesPersistent, non-propagating disturbances in atmospheric flow that are fixed in geographical location, often...
• Stationary frontA front between warm and cold air masses that is moving very slowly or not at all.
• Stationary orbitAn orbit in which a satellite remains in a fixed position relative to the surface of the celestial body it is...
• Stationary processA time series or stochastic process whose underlying statistical distribution does not change over time. This...
• Stationary sourceA fixed location or facility that emits air pollutants into the atmosphere, as opposed to mobile sources like...
• Stationary time seriesA series of data points indexed in time order where the statistical properties, such as the mean, variance...
• Stationary waveA wave whose phase stays fixed relative to the ground, so its crests and troughs remain at the same places...
• Stationary-state hypothesisAn assumption in chemical kinetics that a short-lived reactive intermediate is destroyed about as fast as it...
• Stationary-wave lengthThe wavelength at which a Rossby wave stays fixed relative to the ground, found where its westward phase...
• Station-year methodA way of estimating how often rare rainfall or flood events occur by pooling the records of several stations...
• StatisticA numerical value calculated from a sample of data, used to estimate a characteristic of a larger population...
• StatisticalRelating to the collection, analysis, interpretation, presentation, and organization of data, often involving...
• Statistical forecastA weather prediction generated by applying statistical relationships derived from historical meteorological...
• Statistical independenceA condition where the occurrence of one event or variable does not influence the probability of another event...
• Statistical-dynamical modelA type of climate or weather model that combines statistical relationships derived from observational data...
• StatisticsThe scientific discipline concerned with the collection, analysis, interpretation, presentation, and...
• STBLStable
• SteadinessA measure of the constancy of a meteorological variable, particularly wind direction or speed, over a given...
• Steady flowA type of fluid motion where the velocity, pressure, and other fluid properties at any given point in space...
• Steady stateA condition within a system where all variables and properties remain constant over time, even though there...
• SteamWater in its gaseous phase, formed when liquid water reaches its boiling point or evaporates. It is a...
• Steam devilsSmall, rapidly rotating columns of visible water vapor that form over warm bodies of water, such as lakes or...
• Steam fogA type of fog that forms when cold, dry air moves over a relatively warm body of water. The warm water...
• SteepnessThe ratio of a wave's height to its wavelength, a measure of how sharply peaked the wave is. For deep-water...
• SteeringThe process by which large-scale atmospheric flow patterns influence the movement of smaller weather systems...
• Steering currentsSame as Steering Winds; a prevailing synoptic scale flow which governs the movement of smaller features...
• Steering flowThe ambient large-scale atmospheric current that dictates the movement of smaller weather systems embedded...
• Steering levelAn atmospheric height or pressure level considered most representative of the large-scale flow that guides...
• Steering lineThe line of convergence ahead of a low-pressure centre in the Norwegian cyclone model, along which warm air...
• Steering windsSame as Steering Currents; A prevailing synoptic scale flow which governs the movement of smaller features...
• Stefan-Boltzmann constantA fundamental physical constant that relates the total energy radiated per unit surface area of a black body...
• Stefan-Boltzmann lawA physical law stating that the total energy radiated per unit surface area of a black body across all...
• Stellar crystalA common type of ice crystal characterized by a six-pointed, star-like shape with intricate branching...
• Stem flowThe portion of precipitation that flows down the trunks or stems of plants to the ground. This process...
• Step functionA mathematical function that remains constant over intervals and changes value abruptly at specific points...
• SteppeA vast, treeless grassland biome characterized by semi-arid conditions and short grasses. These regions...
• Steppe climateA type of dry climate characterized by semi-arid conditions, where precipitation is too low to support a...
• Stepped leaderThe initial, invisible discharge of electrons that propagates downwards from a thundercloud in a series of...
• SteradianThe standard unit of solid angle, used to describe the two-dimensional angular span in three-dimensional...
• Stereographic imageAn image or map projection that represents a spherical surface onto a plane, preserving angles but distorting...
• Stereographic projectionA conformal map projection that projects points from a sphere onto a plane from a perspective point on the...
• Stereoscopic imageA pair of two-dimensional images that, when viewed together, create a perception of three-dimensional depth...
• Stevenson screenA white, louvered wooden box designed to house meteorological instruments, such as thermometers and...
• STFRStratus Fractus
• STGStrong
• Stiff systemA system of ordinary differential equations where some components of the solution decay much more rapidly...
• Stikine windA strong, cold, and dry katabatic wind that flows from the interior of British Columbia, Canada, through the...
• Stilling basinIn hydrologic terms, a basin constructed to dissipate the energy of fast-flowing water (e.g., from a spillway...
• Stilling-well gaugesInstruments used to measure water levels, typically in oceans, lakes, or rivers, that are housed within a...
• Still-water levelThe elevation the sea or lake surface would have in the absence of waves, including the astronomical tide and...
• STJSubtropical Jet - this jet stream is usually found between 20° and 30° latitude at altitudes between 12 and...
• STLTSatellite
• STMStratiform
• STNRYStationary
• StochasticDescribing a process or system that involves random variables or elements, where outcomes are not entirely...
• Stochastic hydrologyThe branch of hydrology that applies probabilistic and statistical methods to analyze and model hydrological...
• Stochastic modelA mathematical model that incorporates random variables or probabilistic elements to represent processes...
• Stochastic particle modelingA computational method that simulates the movement and evolution of individual particles within a fluid or...
• Stochastic processA collection of random variables indexed by time or space, representing a system whose state evolves...
• StokeA CGS unit of kinematic viscosity, defined as one square centimeter per second. It measures a fluid's...
• Stokes waveA non-linear wave solution for water waves on the surface of an incompressible, inviscid fluid, representing...
• Stokes's driftThe net forward transport of fluid particles in a wave, even though the wave itself may not be translating...
• Stokes's drift velocityThe net displacement of a fluid parcel over one wave period in a progressive wave, even though the wave...
• Stokes's lawA physical law describing the drag force exerted on a small spherical particle moving through a viscous fluid...
• Stokes's theoremA fundamental theorem in vector calculus that relates the integral of the curl of a vector field over a...
• Stomatal resistanceThe resistance to the diffusion of water vapor and carbon dioxide through the stomata, which are small pores...
• StoopingAn atmospheric mirage that makes distant objects appear vertically compressed or shorter than they actually...
• StoplogsIn hydrologic terms, large logs, timbers or steel beams placed on top of each other with their ends held in...
• Storage coefficientA dimensionless aquifer property equal to the volume of water an aquifer releases from or takes into storage...
• Storage curveA graphical representation showing the relationship between the volume of water stored in a reservoir or...
• Storage equationA mathematical expression that quantifies the change in the amount of a substance within a defined system...
• Storage ratioA hydrological parameter that compares the volume of water stored in a reservoir or basin to another relevant...
• StormA disturbance of the atmosphere marked by strong winds, precipitation, thunder and lightning, or other severe...
• Storm chaserAn individual who pursues severe weather events, such as thunderstorms, tornadoes, and hurricanes, for the...
• Storm dataThis National Climatic Data Center (NCDC) monthly publication documents a chronological listing, by states...
• Storm durationThe total time period over which a weather system exhibits characteristics of a storm, from its initial...
• Storm modelA mathematical or computational representation of atmospheric processes that simulate the formation...
• Storm motionThe speed and direction at which a thunderstorm travels.
• Storm relativeMeasured relative to a moving thunderstorm, usually referring to winds, wind shear, or helicity.
• Storm relative mean radial velocity map(SRM): This WSR-88D radar product depicts a full 360º sweep of radial velocity data with the average motion...
• Storm relative mean radial velocity regi(SRR): This WSR-88D radar product depicts a 27 nm by 27 nm region of storm relative mean radial velocity...
• Storm scaleReferring to weather systems with sizes on the order of individual thunderstorms. See synoptic scale and...
• Storm surgeAn abnormal rise in sea level generated by a storm, over and above the predicted astronomical tide. This...
• Storm tideThe total observed water level during a storm, equal to the astronomical tide plus the storm surge, measured...
• Storm total precipitationThis radar image is an estimate of accumulated rainfall since the last time there was a one-hour, or more...
• Storm trackThe path or trajectory followed by a weather system, such as a tropical cyclone or an extratropical cyclone...
• Storm tracking informationThis WSR-88D radar product displays the previous, current, and projected locations of storm centroids...
• Storm transpositionA meteorological technique used in hydrological design to estimate extreme precipitation for a specific basin...
• Storm warningAn alert issued by a meteorological agency to inform the public and mariners of an impending severe weather...
• Storm watchA watch for an increased risk of a storm force wind event for sustained surface winds, or frequent gusts, of...
• Storm waveAn ocean wave generated by strong winds associated with a significant weather system, such as a tropical...
• Storm windThe strong winds associated with a storm system, typically exceeding a certain threshold for sustained speed...
• Storm-relative environmental helicityA measure of the potential for a rotating updraft (mesocyclone) within a thunderstorm, calculated from the...
• Storm-warning signalA visual or auditory indicator used to alert mariners and coastal communities to the approach of severe...
• Storm-warning towerA tall structure equipped with lights or flags to display warnings of approaching severe weather conditions...
• Stormwater dischargeIn hydrologic terms, precipitation that does not infiltrate into the ground or evaporate due to impervious...
• STPStandard Temperature and Pressure, a set of reference conditions used for comparing gas properties. It is...
• Straight-line hodographThe name pretty well describes what it looks like on the hodograph. What causes this shape is a steady...
• Straight-line windA strong, non-rotational wind that spreads outward from a thunderstorm's downdraft, causing damage in a...
• Straight-line Winds, see Straight-line wind
• Strain tensorA mathematical object that describes the deformation of a fluid parcel or continuous medium at a given point...
• StratificationThe layering of a fluid, such as the atmosphere or ocean, into distinct horizontal strata based on...
• Stratified fluidA fluid that exhibits distinct layers with varying densities, typically arranged such that denser fluid lies...
• StratiformDescribing clouds that are widespread, flat, and sheet-like in appearance, covering a broad area of the sky...
• Stratiform cloudA type of cloud characterized by its extensive horizontal development and relatively uniform base, appearing...
• Stratiform precipitation areaA region within a weather system where precipitation falls from stratiform clouds, characterized by its...
• Stratiform rings and bandsThese occur between the active convective bands of a hurricane outside of the eye wall. Inner stratiform...
• StratiformisA cloud species characterized by its formation into extensive horizontal sheets or layers. This species name...
• StratocumulusA low-level cloud type that appears as a patchy or sheet-like layer of rounded masses or rolls, with clear...
• Stratocumulus stratiformisA specific cloud type and species combination, referring to stratocumulus clouds that are arranged in a...
• StratopauseThe boundary layer in the Earth's atmosphere that marks the top of the stratosphere and the beginning of the...
• StratosphereThe layer of the Earth's atmosphere situated above the troposphere and below the mesosphere, characterized by...
• Stratospheric Aerosol Gas ExperimentA series of NASA satellite instruments designed to measure the vertical distribution of aerosols, ozone...
• Stratospheric Aerosol MeasurementA satellite-based experiment designed to measure the concentration and distribution of aerosols in the...
• Stratospheric and Mesospheric SounderAn infrared limb-scanning radiometer flown on the Nimbus 7 satellite, launched in 1978, that measured thermal...
• Stratospheric couplingThe dynamic and chemical interactions between the stratosphere and other atmospheric layers, particularly the...
• Stratospheric oscillationA periodic variation in atmospheric parameters, such as wind direction and temperature, within the...
• Stratospheric ozoneIn the stratosphere, ozone has beneficial properties where it forms an ozone shield that prevents dangerous...
• Stratospheric Sounding UnitA three-channel infrared radiometer flown on NOAA polar-orbiting satellites from TIROS-N in 1978 that...

1,275 of 10,702 terms in Meteorology and atmospheric science terminology (MLC-0110). Request the full dataset.