term
stringlengths 1
63
⌀ | category
stringclasses 15
values | label
int64 0
1
| definition
stringlengths 5
3.18k
⌀ |
|---|---|---|---|
misocyclone | Space and Astronomy | 1 | A vortex with a width between 40 metres (130 ft) and 4 kilometres (2.5 mi), which in the strictest sense includes waterspouts and landspouts. |
mixed cloud | Space and Astronomy | 1 | A cloud composed of both liquid water droplets and ice crystals (e.g. altostratus, cumulonimbus, and nimbostratus), as opposed to a warm cloud. |
mixing ratio | Space and Astronomy | 1 | A measure of atmospheric moisture content, usually expressed as the dimensionless ratio of the mass of water vapor in a given parcel of air to the unit mass of dry air (i.e. grams of water vapor per kilogram of dry air). |
mock sun | Space and Astronomy | 1 | See parhelion. |
modified fujita scale | Space and Astronomy | 1 | An update to the original Fujita scale from 1971 proposed by Ted Fujita in 1992. |
moist adiabat | Space and Astronomy | 1 | See saturated adiabat. |
moist adiabatic lapse rate | Space and Astronomy | 1 | See saturated adiabatic lapse rate. |
moisture convergence | Space and Astronomy | 1 | An area where moisture concentrates due to the air flow near the surface. |
mountain-gap wind | Space and Astronomy | 1 | See gap wind. |
multicellular thunderstorm | Space and Astronomy | 1 | A thunderstorm consisting of more than one convection cell, i.e. more than one circulating system of updrafts and downdrafts. |
moisture | Space and Astronomy | 1 | The presence of liquid, especially water, within a body or substance, often in trace amounts. Moisture in the air in the form of water vapor underlies the concept of humidity. |
monsoon | Space and Astronomy | 1 | 1. An abrupt seasonal wind reversal accompanied by corresponding changes in precipitation. |
murus | Space and Astronomy | 1 | See wall cloud. |
nacreous cloud | Space and Astronomy | 1 | A rare type of polar stratospheric cloud that forms at altitudes of 24–30 kilometres (79,000–98,000 ft), usually in high-latitude regions. These clouds are normally lenticular in form but may resemble cirrus, and often exhibit brilliant iridescence similar to mother-of-pearl shortly after sunset or before sunrise. |
national severe storms forecast center | Space and Astronomy | 1 | A predecessor forecasting center to the Storm Prediction Center that was located in Kansas City, Missouri. |
nssfc | Space and Astronomy | 1 | A predecessor forecasting center to the Storm Prediction Center that was located in Kansas City, Missouri. |
national severe storms laboratory | Space and Astronomy | 1 | A NOAA lab in Norman, Oklahoma tasked with researching severe weather. |
nssl | Space and Astronomy | 1 | A NOAA lab in Norman, Oklahoma tasked with researching severe weather. |
national tornado database | Space and Astronomy | 1 | The official NOAA record of all known tornadoes within the United States from 1950 to present. |
national weather service | Space and Astronomy | 1 | The national meteorological agency of the United States, tasked with providing weather forecasts, warnings of severe weather, and other weather-related services to organizations and the public for the purposes of protection, safety, and general information. |
nws | Space and Astronomy | 1 | The national meteorological agency of the United States, tasked with providing weather forecasts, warnings of severe weather, and other weather-related services to organizations and the public for the purposes of protection, safety, and general information. |
neap tide | Space and Astronomy | 1 | A small-amplitude oceanic tide of minimum tidal range occurring semi-monthly near the times when the Moon is in quadrature, i.e. the first and third quarters. |
negative tilt | Space and Astronomy | 1 | The angular displacement of a trough line such that the axis of the trough is rotated clockwise from a north–south meridian (as opposed to the counterclockwise rotation of a positively tilted trough); in the Northern Hemisphere, negative tilt corresponds to a northwest-to-southeast orientation. Most troughs begin with a positive tilt and gradually become neutral (north–south) and then negatively tilted as the flow of cold air distorts their shape. Positive tilt thus indicates the building phase of the trough, when clouds and precipitation develop, and negative tilt indicates the dissipation of its energy, when the most severe weather occurs. |
nephology | Space and Astronomy | 1 | The scientific study of clouds. |
nephoscope | Space and Astronomy | 1 | A scientific instrument used to measure the altitude, direction, and velocity of atmospheric clouds relative to a point on the ground directly below them. |
nimbostratus | Space and Astronomy | 1 | A genus of cloud occurring at low or middle altitudes, typically between 0.5 and 5.5 kilometres (1,600 and 18,000 ft), and often appearing as a dull, dark gray, ragged, nearly uniform sheet or layer that obscures the Sun and produces more or less continuously falling light to moderate precipitation but no lightning or thunder. Low, ragged fractus clouds frequently occur below nimbostratus and may or may not merge with it. |
ns | Space and Astronomy | 1 | A genus of cloud occurring at low or middle altitudes, typically between 0.5 and 5.5 kilometres (1,600 and 18,000 ft), and often appearing as a dull, dark gray, ragged, nearly uniform sheet or layer that obscures the Sun and produces more or less continuously falling light to moderate precipitation but no lightning or thunder. Low, ragged fractus clouds frequently occur below nimbostratus and may or may not merge with it. |
nonadiabatic process | Space and Astronomy | 1 | See diabatic process. |
nor'easter | Space and Astronomy | 1 | A macro-scale extratropical cyclone, especially one which impacts the middle and north Atlantic coasts of North America. The name derives from the direction of the winds that most strongly affect the eastern seaboard between the months of October and March. Such storms are often accompanied by very heavy rain or snow, which can cause severe coastal flooding, and hurricane-force winds. |
nor'west arch | Space and Astronomy | 1 | A conspicuous high-altitude arch-shaped cloud formation that appears regularly in otherwise clear blue skies above the east coast of New Zealand's South Island, when a strong, hot, northwesterly föhn wind (known as "The Nor'wester") pushes cooling moist air over the Southern Alps. |
normal | Space and Astronomy | 1 | The average value of a meteorological element (e.g. temperature, precipitation, humidity) over a given period of time, most commonly three consecutive 10-year intervals totaling 30 years. |
northern lights | Space and Astronomy | 1 | See aurora. |
obscuring phenomena | Space and Astronomy | 1 | Any atmospheric phenomenon exclusive of clouds that restricts vertical visibility, including various hydrometeors such as rain and snow as well as lithometeors such as dust and sand. |
occluded front | Space and Astronomy | 1 | A type of front formed during the process of cyclogenesis when a cold front overtakes a warm front. Occluded fronts usually form around mature low-pressure areas when a warm air mass is physically separated (or "occluded") from the cyclonic center at the Earth's surface by the intervention of a cooler air mass; the warmer air is lifted into a trough of warm air aloft. In surface weather analysis, occluded fronts are symbolized by various combinations of the symbols for cold and warm fronts. |
ocean current | Space and Astronomy | 1 | Any regular, permanent or semi-permanent movement or flow of ocean water, either in a cyclic pattern or as a continuous stream along a defined path. Ocean currents are generally driven by wind or by geostrophic forces related to seawater density gradients. They are major transporters of the heat introduced by solar radiation, usually moving warm water from the tropics to higher latitudes and returning cold water in the opposite direction, by which they exert an important influence on climate and weather phenomena across the world. |
oceanic climate | Space and Astronomy | 1 | See marine climate. |
offshore current | Space and Astronomy | 1 | Any ocean current that flows parallel to, or away from, the coastline of a landmass. |
offshore wind | Space and Astronomy | 1 | Any wind that blows from land out over a body of water, e.g. a land breeze. Contrast onshore wind. |
okta | Space and Astronomy | 1 | A unit of measurement used to describe the amount of cloud cover at a given location in terms of how many eighths of the sky are covered in clouds, ranging from 0 oktas (completely clear) to 8 (completely overcast) or sometimes 9 oktas (indicating that the sky is obstructed from view). |
onshore wind | Space and Astronomy | 1 | Any wind that blows from a body of water to land, e.g. a lake or sea breeze. Contrast offshore wind. |
orographic cloud | Space and Astronomy | 1 | Any cloud whose form and extent is determined by the effects of high-elevation terrain upon the passing flow of air, especially the forced uplift of moist air as it passes over hills or mountains. As the rising air mass encounters reduced atmospheric pressures, adiabatic cooling commonly results in condensation and precipitation. Orographic clouds are usually very slow-moving or stationary; examples include lenticular clouds and cap clouds. |
orographic lift | Space and Astronomy | 1 | The forced ascent of an air mass as it passes over a topographic barrier such as a range of hills or mountains. If the air is moist, the uplift may result in adiabatic cooling, leading to saturation, condensation, and the formation of orographic clouds and often precipitation. |
overcast | Space and Astronomy | 1 | The condition of cloud clover wherein clouds obscure at least 95% of the sky. The type of cloud cover that qualifies as overcast is distinguished from obscuring surface-level phenomena such as fog. |
overrunning | Space and Astronomy | 1 | The action of an air mass aloft, often relatively warm, moving over another air mass of greater density at the surface, as occurs in a warm front. |
overshooting top | Space and Astronomy | 1 | A distinct, bulging protuberance produced by a vigorous updraft that rises above the top of the anvil of a cumulonimbus cloud. Overshooting tops are generally short-lived, but those that persist may indicate the potential for strong thunderstorms and severe weather. |
outflow | Space and Astronomy | 1 | Air that flows outwards (away from) a storm system. Outflow typically radiates from thunderstorms in the form of a wedge of rain-cooled air, which is often delineated by a low, thick cloud preceded by a gust front, apparent both from the ground and in weather radar imagery. The altitude at which the outflow occurs is strongly correlated with the intensity and persistence of large storm systems such as tropical cyclones. |
outflow boundary | Space and Astronomy | 1 | The boundary between the cooled outflow air from a thunderstorm and the air of the surrounding environment, similar to a cold front. New thunderstorms often develop along outflow boundaries. |
ozone layer | Space and Astronomy | 1 | A region of the Earth's atmosphere containing relatively high concentrations of the gaseous chemical ozone (O3) and which is responsible for absorbing more than 97 percent of the Sun's incoming medium-frequency ultraviolet (UV) radiation. The ozone layer is found mainly in the lower portion of the stratosphere, between approximately 15 and 35 kilometres (9.3 and 21.7 mi) in altitude, although its thickness varies seasonally and geographically. |
pancake ice | Space and Astronomy | 1 | A form of ice that consists of round, flat pieces of ice with elevated rims, with diameters ranging from 30 cm (12 in) to 3 m (9.8 ft), and thicknesses of up to 10 cm (3.9 in). |
parhelion | Space and Astronomy | 1 | An optical phenomenon in which a patch of bright light is visible along the main 22° halo around the Sun, commonly occurring as a pair of such patches with one on either side of the solar disk; the halo itself is not always visible. More rarely, parhelia may occur at other points on the parhelic circle. They are caused by the refraction of sunlight by airborne ice crystals with diameters less than 30 μm (0.0012 in), e.g. those present in cirrus or cirrostratus clouds. |
pascal | Space and Astronomy | 1 | The SI derived unit of pressure, defined as one newton per square metre. In meteorology, measurements of atmospheric pressure are often given in hectopascals (hPa) or kilopascals (kPa). |
pa | Space and Astronomy | 1 | The SI derived unit of pressure, defined as one newton per square metre. In meteorology, measurements of atmospheric pressure are often given in hectopascals (hPa) or kilopascals (kPa). |
pascal's law | Space and Astronomy | 1 | A hydrostatic principle which states that pressure applied to a confined incompressible fluid (e.g. air) is transmitted equally and undiminished to every portion of the fluid and to the walls of the containing vessel. |
pearson scale | Space and Astronomy | 1 | A tornado rating scale developed by Allen Pearson differentiating path length (P) and path width (P) to accompany NOAA Fujita scale (F) ratings. |
pedestal cloud | Space and Astronomy | 1 | See wall cloud. |
pentad | Space and Astronomy | 1 | A period of five consecutive days sometimes used in preference to the seven-day week in the analysis of meteorological data because it divides conveniently into the number of days (365) in a standard year. |
period of record | Space and Astronomy | 1 | The length of time during which a specific meteorological element (e.g. temperature, humidity, precipitation, etc.) has been officially observed and recorded at a particular place. |
perlucidus | Space and Astronomy | 1 | A cloud variety characterized by a widespread sheet or patch of cloud with distinct gaps between the cloud elements such that the Sun, Moon, clear sky, or overlying clouds are visible from the ground. It is most often applied to stratocumulus and altocumulus. |
photometeor | Space and Astronomy | 1 | Any bright object or other optical phenomenon appearing in the Earth's atmosphere when sunlight or moonlight creates a reflection, refraction, diffraction, or interference under particular circumstances. Common examples of photometeors include halos, coronae, rainbows, crepuscular rays, and sun dogs. |
physical meteorology | Space and Astronomy | 1 | A branch of meteorology concerned with the structure and composition of the atmosphere and the various optical, electrical, acoustical, and thermodynamic phenomena that characterize it, including aerosols and clouds, precipitation, and electromagnetic radiation. |
pileus | Space and Astronomy | 1 | A small accessory cloud, appearing as a smooth, shallow, lenticular "cap", that forms above or attached to the top of a cumulus or cumulonimbus cloud. Pileus clouds are formed when moist air above the parent cloud is cooled to its dew point by a strong updraft, and are good predictors of thunderstorms; a pileus atop a cumulus cloud often foreshadows its transformation into a cumulonimbus cloud. |
pilot balloon | Space and Astronomy | 1 | See ceiling balloon. |
pilot report | Space and Astronomy | 1 | An inflight report by an aircraft pilot or crew member of the weather experienced by the aircraft. A complete coded report typically includes information about the location and/or extent of reported weather phenomena; the time of observation; a description of the phenomena; the altitude of the phenomena; and the type or status of the aircraft. |
pirep | Space and Astronomy | 1 | An inflight report by an aircraft pilot or crew member of the weather experienced by the aircraft. A complete coded report typically includes information about the location and/or extent of reported weather phenomena; the time of observation; a description of the phenomena; the altitude of the phenomena; and the type or status of the aircraft. |
polar high | Space and Astronomy | 1 | An extensive high-pressure area across the polar latitudes of either the Northern or Southern Hemisphere which acts as a source of very cold and generally dry air. The anticyclone over the Arctic, known as the Arctic high, is generally seasonal, while that over Antarctica, known as the Antarctic high, is semi-permanent. |
polar low | Space and Astronomy | 1 | A relatively small-scale, non-frontal, migratory low-pressure system that occurs in the polar latitudes of either the Northern or Southern Hemisphere. Such systems are secondary depressions that form over oceans poleward of the polar front, most commonly during the local winter, and can produce blustery, snowy conditions. |
polar front | Space and Astronomy | 1 | Either of the two semi-permanent, semi-continuous boundaries separating warm, moist tropical air from cold, dry polar air in the middle latitudes of the Northern and Southern Hemispheres. The northern polar front can often be traced as a continuous line of several thousand kilometers over the North Atlantic and North Pacific Oceans. It is the most significant front in terms of air mass contrast and susceptibility to cyclonic disturbance. |
polar vortex | Space and Astronomy | 1 | Either of the two very large, persistent, rotating, upper-level low-pressure areas suspended in the Earth's atmosphere near the geographic poles. The polar vortices predictably strengthen during their local winter and weaken during their local summer as the temperature contrast between the poles and the Equator changes. When either vortex is weak, high-pressure zones of lower latitudes may push poleward, driving the vortex, jet stream, and masses of cold, dry polar air into the mid-latitudes, which can cause sudden, dramatic drops in temperature known as cold waves. |
power flash | Space and Astronomy | 1 | A sudden bright light caused when an overhead power line is severed or especially when a transformer explodes. Severe weather is one of the most common causes. |
precipitable water | Space and Astronomy | 1 | The depth of water, in millimeters or inches, that could be measured if all of the water in a column of the atmosphere were precipitated as rain. |
precipitation | Space and Astronomy | 1 | Any product of the condensation of atmospheric water vapor that falls by gravity, the main forms of which include rain, sleet, snow, hail, and graupel. Precipitation occurs when a portion of the atmosphere becomes locally saturated with water vapor such that the water condenses into liquid or solid droplets and thus "precipitates" out of the atmosphere. |
pressure gradient | Space and Astronomy | 1 | The horizontal or vertical rate of change of barometric pressure in the atmosphere, usually expressed in hectopascals (hPa) per metre; the term is also sometimes used more loosely to denote simply the magnitude of the gradient within a pressure field. The three-dimensional pressure gradient vector is usually resolved into its vertical and horizontal components. |
pressure gradient force | Space and Astronomy | 1 | The force experienced by a unit mass of air in response to differences in atmospheric pressure in either the horizontal or vertical plane, i.e. a pressure gradient, such that air parcels are accelerated away from regions of high pressure and toward regions of low pressure. A strong pressure gradient force leads to intense atmospheric flows and strong winds. |
pgf | Space and Astronomy | 1 | The force experienced by a unit mass of air in response to differences in atmospheric pressure in either the horizontal or vertical plane, i.e. a pressure gradient, such that air parcels are accelerated away from regions of high pressure and toward regions of low pressure. A strong pressure gradient force leads to intense atmospheric flows and strong winds. |
pressure system | Space and Astronomy | 1 | A relative peak or lull in the spatial distribution of sea-level atmospheric pressure. High- and low-pressure systems evolve by the interactions of temperature, moisture, and solar radiation in the atmosphere, and are directly responsible for most local weather phenomena. |
prevailing winds | Space and Astronomy | 1 | The predominant winds encountered at a particular point or region of the Earth's surface, identified by their source and direction. Though wind speed and direction can vary widely for a given location at a given time, the prevailing winds represent the primary trend in the characteristics of local winds averaged over a long period of time. They are influenced both by global patterns of atmospheric air movements and by local topography. |
psychrometrics | Space and Astronomy | 1 | The field of engineering concerned with the physical and thermodynamic properties of gas-vapor mixtures, especially the mixture of air and water vapor. |
pulse storm | Space and Astronomy | 1 | A thunderstorm that produces brief but strong updrafts, common in humid areas of the continental United States during the summer. These storms are often associated with severe weather, particularly sudden and intense wind gusts, very large hailstones which grow continuously as they are repeatedly moved up and down within the storm, and flash flooding. |
pyranometer | Space and Astronomy | 1 | A type of actinometer used to measure solar irradiance on a planar surface and solar flux density in the hemisphere above. |
q vector | Space and Astronomy | 1 | In quasi-geostrophic and semi-geostrophic theory, a horizontal vector which appears in the omega equation and tends to point in the direction of rising air. If Q Q} points toward warm air, the geostrophic flow is frontogenetic; if it points toward cold air, the geostrophic flow is frontolytic. |
quantitative precipitation estimation | Space and Astronomy | 1 | A method of estimating the approximate amount or rate of precipitation that has fallen at a location or across a region based on radar measurements or satellite data. |
qpe | Space and Astronomy | 1 | A method of estimating the approximate amount or rate of precipitation that has fallen at a location or across a region based on radar measurements or satellite data. |
quantitative precipitation forecast | Space and Astronomy | 1 | A prediction of the amount of precipitation that will fall at a given location within a given time period, expressed in units of depth (e.g. inches). |
qpf | Space and Astronomy | 1 | A prediction of the amount of precipitation that will fall at a given location within a given time period, expressed in units of depth (e.g. inches). |
quasi-biennial oscillation | Space and Astronomy | 1 | A marked oscillation in the zonal winds in the lower part of the equatorial stratosphere, in which the direction changes gradually from westerly to easterly and back to westerly with a period that fluctuates between approximately 24 and 30 months. |
qbo | Space and Astronomy | 1 | A marked oscillation in the zonal winds in the lower part of the equatorial stratosphere, in which the direction changes gradually from westerly to easterly and back to westerly with a period that fluctuates between approximately 24 and 30 months. |
quasi-geostrophic approximation | Space and Astronomy | 1 | A form of the primitive equations of motion in which the geostrophic wind, an idealized approximation to the actual wind, is used to simplify the system of momentum and thermodynamic equations known as the quasi-geostrophic equations. These equations are derived from an expansion of terms in powers of the Rossby number, which is presumed small. The quasi-geostrophic approximation is useful in the analysis of extratropical synoptic-scale systems, but less accurate in situations in which the ageostrophic wind plays an important advective role, e.g. near fronts. |
quasi-geostrophic motion | Space and Astronomy | 1 | The flow of a fluid in which an approximate geostrophic balance between the Coriolis force and the pressure gradient force holds, but for which other terms such as the inertial terms involving temporal change or advective acceleration still play a key dynamic role despite their relatively small magnitude. |
quasi-geostrophic theory | Space and Astronomy | 1 | A theory of atmospheric dynamics that involves the quasi-geostrophic approximation in the derivation of the quasi-geostrophic equations. This theory is relatively accurate for synoptic-scale atmospheric motions in which the Rossby number is less than unity, but it cannot accurately describe some local atmospheric structures such as fronts or small, strong low-pressure cells as well as other theories. |
quasi-linear convective system | Space and Astronomy | 1 | See squall line. |
qlcs | Space and Astronomy | 1 | See squall line. |
quasi-stationary front | Space and Astronomy | 1 | A front that is stationary or nearly so; conventionally, a front that is moving at a speed less than about 5 knots (5.8 mph). |
radar echo | Space and Astronomy | 1 | The portion of the pulsed beam of microwave energy emitted by a radar transmitter that is reflected back to the receiver after the signal encounters a specific target or obstruction in the atmosphere, such as individual particles of precipitation. The term may also refer to the backscatter produced by these objects. |
radar imaging | Space and Astronomy | 1 | Any method that uses radar technology to map the location and characteristics of selected environmental phenomena by emitting a pulse of microwave radiation at a target and analyzing the portion that is partially returned by backscattering. Radar imaging is widely used in the atmospheric sciences to create images indicating large-scale spatial patterns of meteorological data, e.g. the intensity and distribution of precipitation, or the height and orientation of wind-driven ocean waves. |
radar meteorology | Space and Astronomy | 1 | A branch of meteorology concerned with the use of primarily ground-based radar technologies for the analysis and prediction of atmospheric phenomena across a wide variety of spatial scales. |
radar winds | Space and Astronomy | 1 | Atmospheric motion detected by using radar to track a target attached to a radiosonde, or by Doppler radar. |
radiation fog | Space and Astronomy | 1 | Fog formed over land, generally at night in moist, calm air under clear skies. The most common type of fog, it is caused by the radiative cooling of the Earth's surface and the lowest layers of the atmosphere when the temperature of the air near the ground decreases below its dew point. Radiation fog occurs most often in the autumn and winter, and is often deepest around sunrise but usually disperses after dawn when heated by solar radiation. |
radiosonde | Space and Astronomy | 1 | A battery-powered scientific instrument released into the atmosphere, usually by a weather balloon, which measures various atmospheric variables and transmits them by radio telemetry to a ground receiver. Radiosondes are essential sources of meteorological data. |
radius of maximum wind | Space and Astronomy | 1 | The distance between the center of a cyclone and its band of strongest winds, often used as a metric for determining a cyclone's potential intensity. |
rmw | Space and Astronomy | 1 | The distance between the center of a cyclone and its band of strongest winds, often used as a metric for determining a cyclone's potential intensity. |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.