Coriolis force

From French Coriolis (“a surname”) + English force, after French scientist Gaspard-Gustave Coriolis.

On a rotor, Coriolis forces will appear whenever there is a radial lengthening or shortening of the blade about the rotational axis, which will be a result of blade flapping or bending.

2006, J. Gordon Leishman, Principles of Helicopter Aerodynamics, page 197:

These terms are generally thought of as due to Coriolis forces, and represent a coupling of the modes of vibration ω₂ and ω₃ Coriolis forces in the rotating molecule. The Coriolis force is a fictitious force which must be introduced if mechanical motion is studied in a rotating coordinate system and the rotation is otherwise overlooked.

2013, C. H. Townes, A.L. Schawlow, Microwave Spectroscopy, page 30:

First, we'll look at a simplified picture of how the pressure gradient and Coriolis forces affect an air parcel high above the ground.

2013, Jack Williams, The AMS Weather Book: The Ultimate Guide to America's Weather, page 56:

(physics, meteorology) A fictitious force apparently exerted on any moving body (including a parcel of air) due to the rotation of the earth, observed as a deflection of the body to the right of its direction of travel (i.e., clockwise) in the Northern Hemisphere, or to the left (anticlockwise) in the Southern Hemisphere; any equivalent apparent force that deflects objects in a rotating reference frame.

Coriolis effect
Gaspard-Gustave Coriolis

Coriolisova síla

apparent force due to the rotation of the earth


tropical depression

en-noun

tropical depression (plural tropical depressions)

(meteorology) organized low-pressure system of thunderclouds with closed surface circulation and maximum sustained winds of less than 34 knots (63 km) per hour.


adiabatic lapse rate

adiabatic lapse rate (plural adiabatic lapse rates)

(meteorology) The rate of decrease of temperature with height of a parcel of dry air lifted upward through the atmosphere with no addition or deletion of heat.


dewpoint

(weather) Alternative spelling of dew point.


geostrophic

en-adj

geostrophic (comparative more geostrophic, superlative most geostrophic)

more geostrophic (comparative)
most geostrophic (superlative)

From Ancient Greek γεω- (geō-, “earth-”) + στροφή (strophḗ, “a turn, bend, twist”) + -ic.

(meteorology) Relating to the balance, in the atmosphere, between the horizontal Coriolis forces and the horizontal pressure forces.

(meteorology) Relating to or arising from the deflective force exerted on the atmosphere due to the rotation of the earth.


geostrophic wind

en-noun

geostrophic wind (plural geostrophic winds)

horizontal pressure gradient force
horizontal pressure gradient force

(meteorology) A wind whose direction and speed are determined by a balance of the horizontal pressure gradient force and the force due to the earth's rotation to the left in the northern hemisphere and to the right in the southern hemisphere.

constant-pressure surface
constant-pressure surface

(meteorology) That horizontal wind velocity for which the Coriolis force exactly balances the horizontal pressure gradient force. The geostrophic wind is thus directed along the contour lines on a constant-pressure surface (or along the isobars in a geopotential surface) with low elevations (or low pressure) to the left in the northern hemisphere and to the right in the southern hemisphere.


gradient wind

constant pressure surface
constant pressure surface

(meteorology) A horizontal wind velocity tangent to the contour line of a constant pressure surface (or to the isobar of a geopotential surface) at or above 2,500 feet (762 meters).


geopotential

It might sound puzzling that the ageostrophic geopotential (or the ageostrophic pressure in z-coordinate) has no impact on the evolution of the vorticity of a quasi-geostrophic disturbance and yet it affects the perturbation kinetic energetics (not globally but locally).

2004, Zhu Xun, Li Xiaofan, Cai Ming, Observation, Theory And Modeling Of Atmospheric Variability, →ISBN, page 13:

(meteorology) The work that must be done at a given altitude in raising a unit mass from sea level to that altitude against the earth's gravitational field.


lapse rate

(meteorology) The rate of change in an atmospheric variable, especially temperature, with increase of height.


nimbostratus

(meteorology) A mid-level cloud, generally formless and dark grey in color, associated with precipitation. Abbreviated Ns.


pillaring

(meteorology) The rapid rising of smoke clouds due to heat generated by burning munitions or existing convection currents.


downdraft

downdrafts (plural)
downdraught (alternative)

(meteorology, American spelling) A strong, downward air current; an air pocket or air hole.


surface boundary layer

surface boundary layer (plural surface boundary layers)

(meteorology) The portion of the atmosphere lying next to the surface of the earth and extending up to between 50 and 100 meters.


stratus

stratus (usually uncountable, plural strati)

Borrowed from Latin stratus. Doublet of strath.

(meteorology) A principal, low-level cloud type in the form of a gray layer with a rather uniform base, usually not associated with precipitation, and capable of producing corona phenomena and a weak, uniform luminance; abbreviated St.


foehn

foehns (plural)
foen (alternative)
föhn (alternative)
fohn (alternative)

Borrowed from German Föhn, from Old High German phonno, from Vulgar Latin faōnius, an alteration of Latin favōnius (“west wind”), from Favōnius (“Roman wind god”).

The foehn, I learned, was first recorded in the Alps but is found all over the world. The Santa Anas contain the occasional foehn, nicknamed “murder winds” and immortalized in Joan Didion's 1965 essay “Los Angeles Notebook"

2011, Claire Dederer, Poser: A Mother's Life in Twenty-Three Yoga Poses, Bloomsbury, page 261:

This is particularly noticeable in Foehn winds—warm winds that descend from mountainous areas down to areas of lower elevation.
Wind patterns considered Foehn include the dry southerly wind blowing through the Alps, Switzerland and across southern Germany. The Sharav or Hamsin winds blowing through the desert in the Middle East are also Foehn winds. The Sirocco winds that blow through Italy and the Mistral winds that blow through southern France are both considered Foehns.

2013, Case Adams Naturopath, Asthma Solved Naturally, Logical Books, page 111:

(meteorology) A similar katabatic wind developing on the lee side of a mountain.


nephology

From Ancient Greek νέφος (néphos, “cloud”) + -logy.

His head's always in the clouds, so he must want to study nephology.

(meteorology) The branch of meteorology that studies clouds.


wet-and-dry-bulb hygrometer

wet-and-dry-bulb hygrometer (plural wet-and-dry-bulb hygrometers)

(meteorology) A hygrometer consisting of two thermometers, the bulb of one of which is kept wet and shows a lower temperature; the relative humidity is obtained from the two temperatures using tables.


psychrometrics

(meteorology, thermodynamics) The measurement or study of the physical and thermodynamic properties of the atmosphere and its water vapour.


air mass

air masses (plural)
airmass (alternative)

After a 227-day drought ending with December temperatures above 90, a polar air mass collided with a wave of damp tropical air, condensed it in seven days of cloudburst.

The mercury has been soaring in the state since the weekend because of an air mass hovering over Queensland.

2013 December 31, Bridie Jabour, The Guardian:

(meteorology) A particular volume of air, especially one having a roughly uniform temperature, pressure and water vapour content.

en:air mass
en:air mass (disambiguation)

massa d'aire

(meteorology) a particular volume of air


dry bulb temperature

dry bulb temperature (countable and uncountable, plural dry bulb temperatures)

dry bulb temperatures (plural)
dry-bulb temperature (alternative)

Coordinate term: wet bulb temperature

(meteorology) Temperature of the free air as measured with a dry thermometer on a sling psychrometer over a grassy surface at a height of approximately 6 feet (1.8 meters).


cold front

(meteorology) The leading edge of an advancing mass of cold air.


warm front

(meteorology) The trailing edge of a retreating mass of cold air.


occluded front

(meteorology) A front that occurs when a cold front overtakes a warm front at the surface and a temperature contrast exists between the advancing and retreating cold air masses.


stationary front

stationary front (plural stationary fronts)

(meteorology) A boundary between air masses that is neither advancing nor retreating


advisory

advisory (countable and uncountable, plural advisories)

(meteorology) Official information issued by the National Weather Service that highlights special weather conditions that are less serious than a warning. They are for events that may cause significant inconvenience, and if caution is not exercised, it could lead to situations that may threaten life and/or property.


rain shadow

As a necessary consequence of this analogous structure, we find no forests eastward of the slopes of the Rocky Mountains and the Cordilleras, or in their "rain shadow," but open steppes...

1876, Oscar Peschel, The Races of Man: and Their Geographical Distribution, D. Appleton & Company, page 422:

A pronounced 'rain shadow' and chinook belt occur on the plateau district in the lee of these mountains.

1896, “Current Notes on Physiography”, in Science, volume 3, number 72, page 732:

In the modern day, the Andes cast a very strong rain shadow, resulting in the extreme aridity of the Atacama Desert.

2022, Thomas Halliday, Otherworlds, Penguin, published 2023, page 59:

(meteorology) An area of diminished precipitation on the lee side of mountains, caused by the prior release of moisture on the windward side.


MCS

mesoscale convective system
mesoscale convective system#English

(meteorology) Initialism of mesoscale convective system.


hoar frost

hoar frost (countable and uncountable, plural hoar frosts)

hoar frosts (plural)
hoarfrost (alternative)
hoar-frost (alternative)

PIE word
 *prustós
From Middle English hore frost, horfrost [and other forms], from hor (“grey; greyish-white”, adjective) (from Old English hār (“grey”), ultimately from Proto-Indo-European *(s)ḱeh₃- (“darkness; shadow”)) + frost (“cold spell, freezing weather, frost; hoar-frost; rime”) (from Old English frost, forst, ultimately from Proto-Indo-European *prustós (“frost”)). The English word is analysable as hoar (“greyish-white; white”, adjective) + frost.

nb...

hoorfrost, hore-forst, hor-forst, hore vrost

compound

On Sunday night, January 23, ſeveral things vvere laid out at the Obſervatory, ſuch as ſheets of brovvn paper, pieces of boards, plates of metal, glaſſes of ſeveral kinds, &c. vvhich all began to contract hoar-froſt ſeemingly as ſoon as each body had time to cool dovvn to the temperature of the air. The ſheets of brovvn paper being ſo thin acquired it ſooneſt, and vvhen beheld in candle-light they became beautifully ſpangled over by innumerable reflections from the ſmall cryſtals of hoar-froſt vvhich had parted from the air.

1780 April 20, Patrick Wilson, “XXVI. An Account of a Most Extraordinary Degree of Cold at Glasgow in January Last; together with Some New Experiments and Observations on the Comparative Temperature of Hoar-frost and the Air near to It, Made at the Macfarlane Observatory Belonging to the College. […]”, in Philosophical Transactions, of the Royal Society of London, volume LXX, part II, London: […] Lockyer Davis, and Peter Elmsly, printers to the Royal Society, →OCLC, pages 468–469:

This striking fact, of the lower temperature of the surface on which dew and hoarfrost are forming, it was always found difficult to explain; for the transition of a body from the state of vapour to the fluid or solid form is always accompanied with an evolution of heat, […] The surface is not warmer in consequence of the formation of the dew or hoarfrost, but the dew or hoarfrost is deposited because the surface is previously cold; and its low temperature, compared with that of the air above, is owing to the discharge of heat by radiation.

1817, John Murray, “Of Caloric”, in Elements of Chemistry. […], 4th edition, volume I, Edinburgh: […] Francis Pillans, […]; London: Longman, Hurst, Rees, Orme, & Brown, →OCLC, book II (Of Repulsion, and the Powers by which It is Produced), section III (Of the Communication and Diffusion of Caloric), page 146:

Hoar frost forms when water vapor sublimates^([sic]) onto a surface. It is the frozen equivalent of dew. […] Conditions leading to hoar frost formation include the movement of vapor within the snowpack, the presence of supersaturated air in crevasses, ice caves, and animal burrows, and the occurrence of clear evenings with high levels of outgoing longwave radiation.

1989, James C. Halfpenny, Roy Douglas Ozanne, “What and Where is Winter?”, in Winter: An Ecological Handbook, Boulder, Colo.: Johnson Books, →ISBN, page 47, column 1:

However, high mountains with a long winter and long dry spells, hoarfrosts and infertile soils are not an ideal environment for some annual crops but are well suited for perennial industrial crops and forest species.

2005, Manh-Cuong Pham, “Conclusions and Policy Implications”, in Land-use Change in the Northwestern Uplands of Vietnam: Empirical Evidence from Spatial Econometric Models and Geo-referenced Analyses and Policy Implications for Sustainable Rural Development, Göttingen: Cuvillier Verlag, →ISBN, page 331:

The samples of hoar frost collected at all the stations contained few NO₃⁻ ions; this may have been because frost forms at night, when the intensity of road traffic is 2–3 times less than during the day. The largest proportion of NO₃⁻ ions was found in the farmland samples of hoar frost; the reason for this may be the application of nitrogen fertilizers in agriculture.

2013, “Rain Water: Atmospheric Deposition”, in Sven Erik Jørgensen, editor, Encyclopedia of Environmental Management, volume I, Boca Raton, Fla.: CRC Press, →ISBN, page 2257, column 1:

(specifically, meteorology) Water vapour which has undergone deposition or desublimation (“transformation directly into ice crystals without first turning into liquid water”) when the air is cold and moist to form a white deposit on exposed surfaces.

brymë

any frozen dew forming a white deposit on exposed surfaces; water vapour which has undergone deposition or desublimation (“transformation directly into ice crystals without first turning into liquid water”) to form a white deposit on exposed surfaces


hard freeze

(meteorology) A freeze sufficiently long and severe to destroy seasonal vegetation and lead to ice formation in standing water and hard ground. 27°F (-3°C) is considered a threshold in the US.


moonbow

From moon + bow, by analogy with rainbow.

Often rainbows by night or moonbows span the lake.

1896, James Wells, Travel-pictures from Palestine, page 94:

Among the rarer optical effects associated with the moon are also moonbows or lunar rainbows.

2010, Bernd Brunner, Moon: A Brief History, unnumbered page:

When the sun shines over Kentucky's Cumberland Falls, the mist creates a rainbow on most days. If the moon shines brightly enough, it can create a moonbow, too!

2011, Colleen Ryckert Cook, Kentucky: Past and Present, page 9:

(meteorology) A rainbow formed by moonlight diffracted by water droplets in the air, usually fainter than a daytime rainbow and with fewer distinguishable colours.


subtropical

extratropical cyclone
extratropical cyclone

(meteorology, of a cyclone) Having some characteristics of a tropical cyclone but also some characteristics of an extratropical cyclone.


flash flood

flash floods (plural)
flashflood (alternative)

LL-Q1860 (eng)-Flame, not lame-flash flood.wav

The West Highland Line reopened for passengers on July 11, following emergency repair works after more than 1,600 tons of material was washed away by a flash flood on June 25.

2020 August 12, Philip Haigh, “Short-term access planning is not in passengers' interest”, in Rail, page 55, photo caption:

One of the most heavily hit regions was Germany’s Ahrweiler district, where flash floods surged through the village of Schuld, washing away six houses and leaving several more on the verge of collapse. The police said at least 50 people had died in Ahrweiler district.

2021 July 15, Melissa Eddy, “Hundreds Missing and Scores Dead as Raging Floods Strike Western Europe”, in The New York Times, →ISSN:

(meteorology) A sudden, rapid flood, usually of short duration and local impact.


space weather

It may sound like science fiction, but heightened solar activity (known as space weather) can affect human technologies not just in space, but also in the air and on the ground.

2023 November 15, Prof. Jim Wild, “This train was delayed because of bad weather in space”, in RAIL, number 996, page 30:

(meteorology) Any phenomena related to the radiation and particles emitted by the Sun, especially in the vicinity of the Earth that may have an effect on the Earth or human activity in the space.


cyclonic

en-adj

cyclonic (comparative more cyclonic, superlative most cyclonic)

more cyclonic (comparative)
most cyclonic (superlative)

(meteorology) Rotating in the same direction as the Earth i.e. anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.


octa

It has been shown that most of the flood-rainy days are associatied with 6-8 octa ScFb, CuSc in the morning and CuSc, ScFb with or without Cb in the afternoon of the previous day.

1935, Indian Science News Association, Science and Culture, Indian Science News Association, Page 93

This method does not give any information on the distribution of clouds in the sky dome. But it presents the advantage of an objective method by eliminating the source of error due to personal appreciation of the fraction of the sky covered by clouds, as is the case in the classical climatorlogical observation of the cloudiness expressed in octa (N = 0 corresponding to cloudless sky and N = 8, to overcast sky in this scale).

1994, Commission of the European Communities, edited by R. Dogniaux, Prediction of Solar Radiation in Areas With a Specific Microclimate, Kluwer Academic Publishers, →ISBN, page 23:

In Figure 4 we compare the photolysis frequencies of different processes in scatter plots, including all measurements from the field campaign over a variety of meteorological conditions (χ = 40-90°, 296-380 DU total ozone, 0-8 octa cloud cover, 9-35 °C ambient temperature).

1998, Ralf Koppmann, Jochen Rudolph, Atmospheric Measurements During Popcorn: Characterisation of the Photochemistry Over a Rural Area, Springer, page 169:

(meteorology) The proportion of the sky that is obscured by clouds, in eighths (one octa means that one eighth of the sky is obscured, two octas that one quarter is obscured, and so on).


ENSO

(meteorology) Acronym of El Niño/La Niña-Southern Oscillation.


squall line

(meteorology) A line of thunderstorms, hundreds of miles long, with squalls at the advancing edge.


parhelic circle

en-noun

parhelic circle (plural parhelic circles)

(meteorology) A luminous halo, each side of the sun parallel to the horizon, caused by refraction of sunlight through ice crystals.


occluded

(meteorology) (of air) forced upwards by colder, denser air


humidex

(Canada, meteorology) A measurement used by Canadian meteorologists to reflect the combined effect of heat and humidity, as the apparent temperature felt by a person.


freezing level

(meteorology) The altitude at which the temperature of the atmosphere is 0°C at a specific location


snow level

The snow level, or altitude in the atmosphere where snow melts to rain, is an important variable for hydrometeorological prediction in mountainous watersheds; yet, there is no operational performance measure associated with snow-level forecasts in the United States.

2009, Allen B. White et al., “Developing a Performance Measure for Snow-Level Forecasts”, in Journal of Hydrometeorology, volume 11, number 3, →DOI:

Snow levels Sunday and Monday are expected to hover about 6,000 feet before dropping to 5,000 feet midweek.

2019 December 20, Hannah Fry, “Rain and snow return to Southern California this weekend. How long will it last?”, in Los Angeles Times:

A surge of moisture moving will produce a wintry mix over the Big Island summits through today. Snow levels are expected to be around 13,000 feet during this time.

2020 December 18, National Weather Service, 335 AM HST Winter Weather Advisory

(meteorology, chiefly Western US) The altitude, in a mountainous region, above which precipitation falls as snow.


weather front

(meteorology) The boundary between two masses of air of different density and/or temperature


temporale

Borrowed from Spanish temporal (“storm”), perhaps via back-formation from the plural temporales.

bor+

Only two storms, Emily and Jennifer, developed over the Pacific; and of these, Emily formed within a temporale, over southern Mexico, that occurred in the wake of hurricane Camille.

1970, Neil F. Frank, “Atlantic Tropical Systems of 1969”, in Monthly Weather Review, volume 98, number 4, page 310:

(meteorology) A rainy wind that blows into Central America from the southwest during the summer, often bringing stormy weather.


étage

Borrowed from French étage. Doublet of stage.

(meteorology) Any of the distinctive forms that a cloud takes relating to the altitude of its base, either "low", "middle", or "high", and designated by the respective prefixes strato-, alto-, and cirro-.


meridional

/mɪˈɹɪdɪənəl/

Borrowed from Middle French meridional, from Latin merīdiōnālis, from merīdiēs (“noon; south”).

(astronomy, geography, meteorology) along a north–south direction, or relative to a meridian; or relating to meridians or a meridian

pohjois–etelä-suuntainen

astronomy, geography, meteorology: along a north–south direction


wind rose

(meteorology) A diagram in which the speed and direction of the winds at a particular location are represented by lines of varying thickness and length superimposed on a compass rose.


microstructure

en-noun

microstructure (countable and uncountable, plural microstructures)

(meteorology, oceanography) Fine-scale structure in such variables as temperature, salinity, velocity, etc.


mesopause

From meso- (“middle”) + -pause (“boundary”).

(meteorology) In the atmosphere, the boundary between the mesosphere and the thermosphere or ionosphere. It is the atmospheric boundary where the temperature reaches its minimum value.

mesopausa

the boundary between the mesosphere and the ionosphere


difluent

en-adj

difluent (comparative more difluent, superlative most difluent)

more difluent (comparative)
most difluent (superlative)

(meteorology) (Of wind) which diverges, especially when viewed on a weather chart


confluent

confluent (comparative more confluent, superlative most confluent)

more confluent (comparative)
most confluent (superlative)

(meteorology, of wind) Converging, especially as viewed on a weather chart.


stratus fractus

(meteorology) Stratus clouds which are scattered or ragged.

bólstraruðningur

stratus clouds which are scattered or ragged


METAR

(aviation, meteorology) Meteorological Aerodrome Report, the aviation routine weather report; a specially encoded weather observation report.


TAF

(meteorology, aviation) Terminal Aerodrome Forecast: a specially encoded weather forecast for a terminal aerodrome


PIREP

(meteorology) Abbreviation of pilot report, a specially encoded weather observation recorded by a pilot mid-flight.


wind chill

en-noun

wind chill (countable and uncountable, plural wind chills)

wind chills (plural)
wind-chill (alternative)
windchill (alternative)

The thermometer says zero, but with the wind chill it's more like minus five.

A steady northwest breeze will keep wind chills in the teens and single digits for the remainder of your weekend.

2021 January 16, Derek Van Dam, “Northeast will be wet and chilly while Southern California should sizzle during holiday weekend”, in CNN:

The air temperature that day was -13 degrees with a wind chill at -48, according to the NFL.

2024 January 13, Ashley R. Williams, “NFL moves Pittsburgh at Buffalo playoff game to Monday due to winter storm, Miami at Kansas City is still on for tonight”, in CNN:

(meteorology) The cooling effect of wind, especially on the human body, which causes the "feels like" temperature to be lower than the thermometer temperature.


zonal kinetic energy

(meteorology) The kinetic energy of the zonal wind at a specified latitude.


zonal wind

(meteorology) The component of a wind along a particular parallel of latitude


meridional wind

meridional wind (plural meridional winds)

(meteorology) The component of a wind along a particular meridian


orographic

(meteorology) Of or pertaining to the effects of mountains on weather.

orografinen

of or pertaining to the effects of mountains on weather


PDS

(meteorology) Initialism of particularly dangerous situation.


breakup

breakups (plural)
break up (alternative)
break-up (alternative)

(Alaska and northern Canada, seasons, time) The time of year during which winter ice covering bodies of water disintegrates; more generally, spring.


pinhole

pinholes (plural)
pin-hole (alternative)

(meteorology) A clipping of pinhole eye, which refers to the compact eye structure associated with intense tropical cyclones.


macrometeorology

Generally, macrometeorology is concerned with weather systems having spatial scales greater than 1000 km and temporal scales on the order of several days or longer.

2013, William R. Cotton, Storm and Cloud Dynamics, volume 44, page ix:

(meteorology) The study of the large-scale behaviour of the atmosphere


cloud up

en-verb

cloud up (third-person singular simple present clouds up, present participle clouding up, simple past and past participle clouded up)

clouds up (present singular third-person)
clouding up (participle present)
clouded up (participle past)
clouded up (past)


advection

en-noun

advection (countable and uncountable, plural advections)

From Latin advectio (“act of bringing”), from advectus (past participle of advehere (“to carry to”), from ad- + vehere (“to convey”)) + -io.

(meteorology, earth science, physical chemistry) The horizontal movement of a body of atmosphere (or other fluid) along with a concurrent transport of its temperature, humidity etc.


extratropical

(meteorology) Lacking or having lost tropical characteristics.


mesoscale

(meteorology, of a weather phenomenon) Roughly 2–200 kilometers in extent; between microscale and synoptic.


storm cloud

storm clouds (plural)
storm-cloud (alternative dated)
stormcloud (alternative)

Uncertainty hangs over the industry like a storm cloud on a summer's day, preventing long-term planning and investment.

2023 March 8, Christian Wolmar, “Labour passes up the chance to deliver a forceful rail policy”, in RAIL, number 978, page 35:

(meteorology) A dark and ominous cloud that appears to indicate a coming storm.

хма́ра

rain cloud with potential to bring a storm — see also cumulonimbus, thundercloud

ជលធរ

cŭəllĕəʼthɔɔ


katabatic

Learned borrowing from Ancient Greek καταιβατός (kataibatós, “down-going, descending”), from κατα- (kata-, “down”) + βαίνω (baínō, “to go”).

lbor

At the field camp, paper-thin tents shudder beneath katabatic blasts of freezing wind, stoves sputter a stingy flame, and a few trudging specks haul shovels through a cold world where extra food and equipment cannot be bought at any price.

2005, Nicholas Johnson, chapter 3, in Big Dead Place, →ISBN:

Penguin colonies that number in millions; nights that run into days, and days that run into nights; katabatic winds that scream down the ice sheets at a terrifying 180 miles per hour, and then remain equally terrifyingly still.

2006 February 24, Tishani Doshi, “Meanwhile: The long view from Antarctica”, in The New York Times, →ISSN:

(meteorology, of airflow) Downslope on a mountainside.


rain gauge

LL-Q1860 (eng)-Flame, not lame-rain gauge.wav

(meteorology) A device used in meteorology to measure rainfall.

шөгуді өлшегіш

şögudı ölşegış


iridescent cloud

en-noun

iridescent cloud (plural iridescent clouds)

polar stratospheric cloud
polar stratospheric cloud


polar stratospheric cloud

polar stratospheric cloud (plural polar stratospheric clouds)

(meteorology) A relatively rare type of clouds that occurs high in the stratosphere; polar stratospheric clouds often resemble mother-of-pearl as they shine in vivid colours, known as irisation


green flash

Coordinate term: blue flash

Frank T. Davies, physicist on board the City of New York, en route to the Antarctic regions with Byrd Antarctic Expedition, reports as follows on a green flash observed off Bermuda on the evening of August 29, 1928.

1929, J. A. Fleming, "Observations of Green Flash," Science, New Series, vol. 69, no. 1785, p. 298

(meteorology, astronomy) A rare phenomenon observed in the morning or evening when the sun is crossing or immediately below the horizon, in which a momentary flash or ray of green light appears above the upper rim of the solar disk, caused by the refraction of light in the atmosphere.


blue flash

(meteorology, astronomy) A very rare phenomenon observed in the morning or evening when the sun is crossing or immediately below the horizon, in which a momentary flash of blue light appears above the upper rim of the solar disk, caused by refraction of light in the atmosphere.


lenticular cloud

lenticular cloud (plural lenticular clouds)

(meteorology) A high-altitude cloud that is shaped like a lens.


ice pellets

(chiefly Canada and US, meteorology) Sleet.


perfect storm

Popularized by the book (1997) and movie (2000) The Perfect Storm.

1796, William Fordyce Mavor, Historical account of the most celebrated voyages, travels, and discoveries ..., p. 161,
But on the 24th of April, the wind again blew a perfect storm, and our other ships of the squadron separated, nor did any of them rejoin the commodore.

1914, Samuel Finley Breese Morse and Edward Lind Morse, Samuel F.B. Morse: His Letters and Journals, p. 190,
Ten o'clock. Beginning to blow hard; taking in sails one after another. — Three o'clock. A perfect storm; the gale a few days ago but a gentle breeze to it.

Hung my head as I lost the war
And the sky turned black like a perfect storm

2014 October 27, Taylor Swift, Imogen Heap, “Clean (Taylor's Version)”, in 1989 (Taylor's Version), performed by Taylor Swift, published 2023 October 27:

(meteorology, informal) A powerful hurricane or other major weather disturbance, especially as produced by a combination of meteorological conditions.


precip

precip (countable and uncountable, plural precips)

(meteorology) Clipping of precipitation.


radarmeteorology

(meteorology) The use of radar in meteorology, especially to track water and ice in clouds


light air

(meteorology, nautical) A light wind with wind speed between 0.3 and 1.5 m/s; a Force 1 wind strength on the Beaufort scale.


teleconnection

(meteorology) A causal link between two or more distant weather systems


feel like

en-verb

feel like (third-person singular simple present feels like, present participle feeling like, simple past and past participle felt like)

feels like (present singular third-person)
feeling like (participle present)
felt like (participle past)
felt like (past)

apparent temperature
apparent temperature#English

(meteorology, impersonal) Denotes the apparent temperature.


tornadocane

(meteorology, informal) A supercell thunderstorm whose radar signature resembles that of a hurricane, with a center free of precipitation; a landphoon.


landphoon

(meteorology, informal) A tropical depression over land whose satellite signature resembles that of a typhoon.


EF

Enhanced Fujita scale
Enhanced Fujita scale

(Canada, US, meteorology) Followed by a number from 0 to 5: initialism of Enhanced Fujita, a rating on the Enhanced Fujita scale used to indicate the intensity of a tornado; it has superseded the Fujita scale.


nebulosity

en-noun

nebulosity (countable and uncountable, plural nebulosities)

With higher powers the field does not appear to be sufficiently large to allow of each streak of nebulosity being compared with the surrounding parts where the nebulosity is not quite so bright.

1868, Lord Oxmantown, An account of the observations on the great nebula in Orion:

If one conceives by analogy all the stars formed in this manner, one can imagine their anterior state of nebulosity itself preceded by other stars in which the nebulous matter was more and more diffuse, the nucleus being less and less luminous and dense.

2007, Stephen Hawking, God Created The Integers: The Mathematical Breakthroughs that Changed History:

(meteorology, astronomy) The characteristic of being nebulous; cloudiness (measured in octas).


pyrocumulus

(volcanology, meteorology) A dense cloud associated with fire or volcanic activity.


microscale

micro scale (alternative)
micro-scale (alternative)

(meteorology) Extending over a relatively small area, particularly less than 1 kilometer; smaller than mesoscale.


breakpoint

(meteorology) A location referred to when issuing watches, warnings, or advisories for specific areas.


barotropic

en-adj

barotropic (comparative more barotropic, superlative most barotropic)

more barotropic (comparative)
most barotropic (superlative)

(meteorology) In which the pressure of the atmosphere is dependent upon its density only.


prog

en-verb

prog (third-person singular simple present progs, present participle progging, simple past and past participle progged)

progs (present singular third-person)
progging (participle present)
progged (participle past)
progged (past)

LL-Q1860 (eng)-Naomi Persephone Amethyst (NaomiAmethyst)-prog.wav

The thermodynamics of this system are progged to be similar to the "surprise" epic Oct 2006 Buffalo, NY lake effect snow event.

(meteorology) To prognosticate; to forecast.


tramontana

tramontanas (plural)
tramontane (alternative)

(weather) A dry, cold north wind in Italy and adjacent Mediterranean areas.


fogbow

(meteorology) A white arc or circle, similar to a rainbow, which can appear in the sky in foggy conditions as sunlight passes through small airborne water droplets.


EFI

(meteorology) Initialism of extreme forecast index.


cloud cover

(meteorology) The percentage or fraction of the sky obscured by clouds.


Pineapple Express

A warm, wet rainstorm—the notorious "Pineapple Express"—hit Western Washington the weekend before Thanksgiving in 1986.

1990 December 1, Hill Williams, “Another Nasty November”, in Seattle Times, retrieved 2008-10-19:

(informal, meteorology) The jetstream and accompanying strong, moist airflow from the vicinity of the Hawaiian Islands to the west coast of North America.


fair off

fair off (third-person singular simple present fairs off, present participle fairing off, simple past and past participle faired off)

fairs off (present singular third-person)
fairing off (participle present)
faired off (participle past)
faired off (past)
fair up (alternative)

They said it was going to fair off later on, but it didn't.


fair up

fair up (third-person singular simple present fairs up, present participle fairing up, simple past and past participle faired up)

fairs up (present singular third-person)
fairing up (participle present)
faired up (participle past)
faired up (past)
fair off (alternative)

They said it was going to fair up later on, but it didn't.


PMSL

mean sea level pressure
mean sea level pressure#English

(meteorology, rare) Abbreviation of mean sea level pressure (derived from the notation P_(MSL)).


geocorona

From geo- + corona. From being the luminous part of the atmosphere, the outermost region of Earth's atmosphere.

(meteorology, plasma physics, space physics, by extension) Analogs of the geocorona; Synonym of protonosphere.

plasma physics; space physics; plasma physics; space physics


aethrioscope

aethrioscopes (plural)
æthrioscope (alternative)

From Ancient Greek αἰθήρ (aithḗr, “air; ether”) in combination with σκοπέω (skopéō, “examine, inspect”).

der

(meteorology) A device for measuring temperature variations due to different atmospheric conditions, such as cloud or clear skies.


anticyclonically

en-adv

anticyclonically (comparative more anticyclonically, superlative most anticyclonically)

more anticyclonically (comparative)
most anticyclonically (superlative)

(meteorology) In an anticyclonic fashion.


LPA

en-noun

LPA (countable and uncountable, plural LPAs)

(Philippines, meteorology) Initialism of low-pressure area.


bioclimate

(biology, meteorology) A climate, as it influences, and is influenced by, biological organisms


hygrothermograph

(physics, meteorology) An instrument that measures, and records, both humidity and temperature.


stratiform

en-adj

stratiform (comparative more stratiform, superlative most stratiform)

more stratiform (comparative)
most stratiform (superlative)

(meteorology) Descriptive of clouds with extensive horizontal development


weathercast

Blend of weather + forecast. Alternatively from weather + -cast, from broadcast.

The official weathercast called for variable cloudiness.

1965 July 29, “It'll Be Scorcher Again”, in Deseret News, Utah, USA, retrieved 2009-02-04, page B1:

Jocular TV weatherman Dave Devall […] announced on last night's 6 o'clock news that he is easing into retirement. […] His last regular weathercast will be April 3.

2009 February 3, “Hot Box: TV worth talking about”, in Toronto Star, retrieved 2009-02-04:

(meteorology) A weather forecast, especially one broadcast by radio or television.


weather report

I remember a holiday of mine being completely ruined one late autumn by our paying attention to the weather report of the local newspaper.

1889, Jerome K. Jerome, chapter 5, in Three Men in a Boat […] :

(meteorology) A description, especially one prepared by a governmental or other authority, of past, present or forecasted meteorological conditions for a particular geographical area.

weerberig

description of forecasted meteorological conditions


stratospherically

en-adv

stratospherically (comparative more stratospherically, superlative most stratospherically)

more stratospherically (comparative)
most stratospherically (superlative)

(meteorology) By way of or in regard to the stratosphere.


lake effect

lake effects (plural)
lake-effect (alternative)

Lake effect storms dumped 108 inches of snow on Oswego in 48 hours.

(meteorology) An effect of large bodies of fresh water on the weather of regions downwind.


dead man walking

en-noun

dead man walking (plural dead men walking)

LL-Q1860 (eng)-Flame, not lame-dead man walking.wav

A phrase traditionally used in U.S. prisons to announce a condemned prisoner being walked to the place of execution. Its use has expanded as a euphemism for anyone facing an impending and unavoidable loss.

(meteorology, slang) A multivortex tornado typically appearing in the form of a human figure walking.


aeroscopy

From Ancient Greek ἁεροσκοπία (haeroskopía, “divination by observing the heavens”), from ἀήρ (aḗr, “air”) + σκοπέω (skopéō, “I examine”).

lbor

(obsolete, meteorology) The branch of meteorology that involves the scientific examination of the various properties and composition of the atmosphere, and their variation


isohume

From iso- + the base of humid. A pseudo-classical coinage.

(meteorology) An isoline connecting places with equal relative humidity.


isobront

From iso- + Ancient Greek βροντή (brontḗ, “thunder”) (see bronto-).

bor

The lines joining the points where the first thunder is heard at the same instant of time are called "isobronts", or lines of equal front.
Sometimes the isobront is taken as the mean of the time when first and last thunder is heard at a place. This is the custom in France.

1895, Thomas Russell, Meteorology, Weather, and Methods of Forecasting, pages 119–120:

(meteorology) An isoline drawn through geographical points at which a given phase of thunderstorm activity occurred simultaneously.

On these charts isobronts, or lines of equal frequency of thunder, were drawn. These are shown in Figs. 1, 2 and 3, the data being expressed as percentages of days on which thunder was heard.

1925, C. E. P. Brooks, “The distribution of thunderstorms over the globe”, in Geophysical Memoirs, number 24, UK Air Ministry, Meteorological Office:

(meteorology) An isoline drawn through geographical points which, on average, experience the same number of thundery days per year.


lightning mapper

en-noun

lightning mapper (plural lightning mappers)

(meteorology) A system that displays a map of the position of recorded or real-time lightning discharges relative to the user or other objects.


graupel

graupel (countable and uncountable, plural graupels)

Borrowed from German Graupel(wetter) (literally “graupel (weather)”). Graupel is a back-formation from graupeln (“to hail (with soft hailstones)”) + -el (diminutive suffix); and graupeln is from Graupe (“hulled grain, pearl barley”) (ultimately from Proto-Slavic *krūpà (“grainy substance; groats; hail”) and Proto-Indo-European *krewp-) + -eln (suffix forming verbs, often with a diminutive or frequentative sense).

der

Is it desirable in giving the falls of hail to draw a distinction between "graupel" and true hail?

1873 April, “The Leipzig Conference”, in Symons’s Monthly Meteorological Magazine, volume VIII, number LXXXVII, London: Edward Stanford, […], →OCLC, page 42:

November.— […] Smart shower of graupel (i.e. frozen snow in pellets), with snow at 9 p.m. on 10th.

1877 January 24 (date written), Frederick E[rnest] Sawyer, “November”, in Meteorology of Brighton, 1876, [Brighton, East Sussex?]: [s.n.], published [1877], →OCLC, page 2:

In a paper in this month's Petermann's Mittheilungen Prof. H. Fritz treats of the Geographical Distribution of Hail. […] [B]alls of true hail hav[e] an icy structure, whereas the balls of graupel are only small pellets of snow. […] With increase in latitude and in height the fall of graupel increases and that of hail decreases, while hailstones of large size are most frequent towards the equator.

1876 November 2, “Notes”, in Nature: A Weekly Illustrated Journal of Science, volume XV, London; New York, N.Y.: Macmillan and Co., →OCLC, page 17:

The steam of the horses and their breath came back in turbid clouds, and the snow, or soft hail (now known as graupel), cut white streaks through them into travellers' eyes, and danced on the roof like lozenges.

1894, R[ichard] D[oddridge] Blackmore, “A Wager”, in Perlycross: A Tale of the Western Hills, London: Sampson Low, Marston, & Company […], →OCLC, page 238:

(uncountable) A precipitation that forms when supercooled droplets of water condense on a snowflake.

برد دقيق

precipitation that forms when supercooled droplets of water condense on a snowflake; small ball of rime resulting from this process

It is established that graupels and hailstones are cone-shaped with rounded apexes and that they become egg-shaped as a result of growth during descent.

1951 September 15, Donald G. Yerg, “Tikhomirov, E., On the Shape of Graupels and Hailstones (O Forme Krupy i Grada). Meteorologiia i Gidrologiia, 2, No. 9: 66–67, 1936”, in Annotated Bibliography on Snow, Ice, and Permafrost […] (SIPRE Report; 12), [Hanover, N.H.]: Snow, Ice, and Permafrost Research Establishment, Corps of Engineers, United States Army, →ISSN, →OCLC, page 340, column 2:

[W]hen an ice or snow crystal collides with supercooled droplets, the droplets will freeze on the surface of the crystal to form rime. […] [C]ontinued riming will eventually produce a particle that is completely covered by rimes such that the original crystal shape can no longer be recognized. The particle now becomes a graupel (sometimes also called a soft hail or snow pellet). […] By convention, a graupel should be smaller than 5 mm in diameter. If it becomes greater than 5 mm in diameter (2.5 mm in radius) it will be called hail.

2013, Pao K[uan] Wang, “The Shape and Size of Cloud and Precipitation Particles”, in Physics and Dynamics of Clouds and Precipitation, Cambridge, Cambridgeshire: Cambridge University Press, →ISBN, page 30:

(countable) A small ball of rime resulting from this process.


CMA

en-noun

CMA (countable and uncountable, plural CMAs)

(China, meteorology, uncountable) Abbreviation of China Meteorological Administration.


churada

(meteorology) A heavy downpour, typical of the Mariana Islands during the winter months.


thermopause

(astronomy, meteorology) The boundary between the thermosphere and the exosphere in a planetary atmosphere.


barograph

Thanks to their barograph, however, they could judge their height above the sea.

1911, Margaret Burnham, The Girl Aviators' Sky Cruise:

At noon the barograph curve turned up and the wind moderated, the sky gradually clearing.

1913, Captain R. F. Scott, Scott's Last Expedition Volume I:

(meteorology) A type of barometer that continuously records air pressure on a sheet or rotating drum


elve

elves (plural)
ELVE (alternative)
ELVES (alternative)

From e(mission of) l(ight and) v(ery low-frequency perturbations from) e(lectromagnetic pulse sources), and to avoid clashing with the acronym ELF (extremely low frequency) used in the same field of science.

It is likely that the first elve was recorded with the Space Shuttle low-light camera.

2006, Martin Füllekrug, Eugene A. Mareev, Michael J. Rycroft, Sprites, elves and intense lightning discharges, page 37:

(astronomy, meteorology) A rapidly expanding disk-shaped region of red luminosity in the ionosphere, lasting less than a thousandth of a second, which occurs high above energetic cloud-to-ground lightning of positive or negative polarity.


silver frost

silver frost (usually uncountable, plural silver frosts)

(meteorology, colloquial) A deposit of glaze on trees, shrubs, and other exposed objects during a fall of freezing precipitation; the product of an ice storm.


Fujita scale

From the Japanese-American meteorologist Tetsuya Theodore "Ted" Fujita (藤田哲也).

(US, meteorology) A scale used to rate the intensity of a tornado; now superseded by the Enhanced Fujita scale.


nowcasting

Spence said: "We have a weather provider, MetDesk, which gives us real-time information - radar analysis of what rain is falling. It's called nowcasting rather than forecasting, with refresh rates every five minutes.

2020 September 9, “Network News: RAIB: 'washout of material' caused Carmont derailment”, in Rail, pages 8–9:

(meteorology) The use or production of nowcasts.


nowcast

A low-probability nowcast was essentially a “No Forecast" , but issued with less confidence.

1988, Third International Conference on the Aviation Weather System, page 208:

(meteorology) A weather forecast predicting the weather for a very short upcoming period, usually only a few hours.


paraselene

paraselene (plural paraselenes or paraselenae)

paraselenes (plural)
paraselenae (plural)

From Ancient Greek παρά (pará, “beside”) + σελήνη (selḗnē, “moon”).

(meteorology) A bright, circular spot, sometimes seen on a lunar halo, caused by refraction through ice crystals.


cloudwise

Cloudwise, it will be densely overcast tomorrow.

(weather) Regarding the clouds or cloud cover


isopycnal

(meteorology, oceanography) A line connecting points of constant density in the ocean or in the atmosphere.


paleotempestology

(meteorology) The study of past tropical cyclone activity by means of geological evidence and historical documentary records.


allobar

From allo- + bar. According to Alfred J. Henry, the meteorology sense was coined in Swedish by Nils Gustaf Ekholm.

Highlighted in Alfred Henry's 1916 manual, Weather Forecasting in the United States, pressure-change charts have their own terminology, with allobar describing an area where the barometric pressure has changed by 0.1 inch or more in 12 hours[…]

1999, Mark Monmonier, Air Apparent: How Meteorologists Learned to Map, Predict, and Dramatize Weather, page 82:

(meteorology) An area where the atmospheric pressure changes.


frontogenesis

(meteorology, oceanography) The formation or strengthening of an atmospheric weather front or of an oceanic front.


shelf cloud

(meteorology) A low, horizontal cloud typically forming at the leading edge of thunderstorm outflow. An arcus type cloud often found along squall lines.


anticyclogenesis

(meteorology) the development or strengthening of anticyclonic circulation in the atmosphere.


cyclolysis

cyclolysis (countable and uncountable, plural cyclolyses)

(meteorology) The weakening or termination of a cyclonic circulation in the atmosphere


anticyclolysis

(meteorology) The weakening or termination of anticyclonic circulation in the atmosphere.


frontolysis

(meteorology) The degeneration or dissipation of an atmospheric weather front.


anemorumbometer

(meteorology) A type of anemometer which records both wind speed and direction.


potential vorticity

potential vorticity (plural potential vorticities)

(meteorology) a quantity which is proportional to the product of vorticity and stratification. When applied to air parcels, aids the understanding of cyclogenesis


cloud genus

(meteorology) Grouping of the standard cloud classification system. Members include cirrus, cirrocumulus, cirrostratus, altocumulus, altostratus, nimbostratus, stratocumulus, stratus, cumulus, and cumulonimbus.


wind speed

Wind speed is measured by the conventional arrangement of three hemispherical cups, mounted at 120 deg. on a shaft which is geared to a cam.

1952 August, “Wind Velocity Records at Dawlish”, in Railway Magazine, page 545:

Like most human activities, ballooning has sponsored heroes and hucksters and a good deal in between. For every dedicated scientist patiently recording atmospheric pressure and wind speed while shivering at high altitudes, there is a carnival barker with a bevy of pretty girls willing to dangle from a basket or parachute down to earth.

2013 June 7, David Simpson, “Fantasy of navigation”, in The Guardian Weekly, volume 188, number 26, page 36:

The climate testing ranged through temperatures of -15°C to 40°C, extreme warming from sunlight, ice, and wind speeds of up to 100kph (62mph) to check the train could still operate.

2023 November 29, Philip Haigh, “New Piccadilly Line trains put to the test”, in RAIL, number 997, page 26:

(meteorology) The local speed of the wind.


uncinus

(meteorology) A cloud species which consists of fine hair-like strands, with hooked terminations. Associated only with cirrus formations.


spissatus

(meteorology) A cloud species which consists of dense, high level strands, which can haze, or block the sun. Associated only with cirrus formations.


castellanus

From New Latin castellānus, from Medieval Latin castellum (“castle, fortress”) + -ānus (“-an: forming adj.”), from castrum (“fort”) + -ellum (“-elle: forming diminutives”). Doublet of Castilian, castellano, castellan, and chatelain.

doublet

Turbulent mixing, evidenced by alto-cumulus castellanus cloud over France, also took place en route and carried dust to high altitudes.

1985 February 14, Dennis Wheeler, “Saharan dust storm over England”, in New Scientist, volume 105, number 1443, page 26:

Over France the altocumuli castellani clouds at medium level indicate a very unstable air mass there, because these clouds often develop into thunderstorms.

1993, Monthly Weather Review - Volume 121, Issues 10-12, page 2709:

But liftoff in warm, moist, unstable air in which condensation is occurring may result in an updraft capped by a towering altocumulus castellanus cloud at 11,000 to 15,000 feet.

1998, Stuart H. Walker, The Sailor's Wind, page 56:

When a layer of cloud rises in distinct turrets with bumpy tops that resemble crenellations, it is of the species known as castellanus—and this one can give an early indication of unsettled weather to come later in the day.

2011, Gavin Pretor-Pinney, The Cloud Collector's Handbook, page 40:

(meteorology) A cloud species which shows vertical formations giving a crenellated appearance, associated with cirrus, cirrocumulus, altocumulus, and stratocumulus genera.


floccus

(meteorology) A cloud species which consists of rounded tufts of cloud, often formed by dissipation from larger cloud species. Associated with cirrus, cirrocumulus, altocumulus, and stratocumulus genera.


nebulosus

(meteorology) a cloud species which consists of a veil of cloud, showing no distinct details. Associated with cirrostratus, and stratus genera.


lenticularis

(meteorology) a cloud species which consists of rounded lens shaped of cloud, often forming near mountains. Associated with cirrocumulus, and altocumulus, and sometimes stratocumulus genera.


irisation

en-noun

irisation (countable and uncountable, plural irisations)

(meteorology) A colorful optical phenomenon seen in iridescent clouds and on the borders of lenticular clouds resembling those seen in soap bubbles and oil on a water surface.


cap cloud

(meteorology) An accessory cloud in the form of a cap which occurs above, or attached to, cumulus, cumulonimbus, and sometimes stratocumulus clouds.


accessory cloud

accessory cloud (plural accessory clouds)

Pileus An accessory cloud of small horizontal extent, in the form of a cap or hood above the top or attached to the upper part of a cumuliform cloud, which often penetrates it.

1982, Michele G. Melaragno, Wind in architectural and environmental design, Van Nostrand Reinhold Company, →ISBN:

(meteorology) A small cloud formation which is found attached to, or close by, a major cloud of one of the cloud genera, which is responsible for its development and continuance.


standing cloud

(meteorology) a small cloud that remains stationary and is related to a geographical feature, such as a mountain. Classified as banner clouds, cap clouds, crest clouds, or lenticular clouds http://amsglossary.allenpress.com


banner cloud

From banner + cloud. From being a banner-like cloud that hangs off a mountain like a flapping flag.

(meteorology) a small, triangular cloud, extending downwind from the peak of a mountain as if a flag, or banner.


crest cloud

(meteorology) a standing cloud, extending downwind from a mountain range, or ridge.


detrainment

detrainment (countable and uncountable, plural detrainments)

(meteorology) The diffusion of air from an organized current into the general atmosphere.


silver thaw

silver thaw (usually uncountable, plural silver thaws)


June gloom

(weather, US, Southern California) Any of several gloomy weather conditions present during June mornings, especially conditions of clouds, cool temperatures, fog, or drizzle.


cavum

Unadapted borrowing from Latin cavum (“a hollow, hole”). Doublet of cave and cavus.


undercast

en-noun

undercast (countable and uncountable, plural undercasts)

LL-Q1860 (eng)-Flame, not lame-undercast.wav

From Middle English undercasten, equivalent to under- + cast.

Undercast is common on Mount Washington.

(meteorology) An unbroken or nearly unbroken cloud layer below the point of observation.


megacryometeor

(meteorology) a very large water ice object that falls from the sky, similar in composition to hailstones


TSRA

(US, meteorology) Abbreviation of thunderstorms with rain.


isentrope

potential temperature
potential temperature

(meteorology) A surface of constant potential temperature


fallstreak

fallstreaks (plural)
fall streak (alternative)

From fall + streak, because they are composed of cloud crystals falling in streaks.

(meteorology) A (part of a) virga; a streak of falling ice crystals that sublimate before reaching the ground.


mammatus cloud

(meteorology) A cellular pattern of pouches hanging underneath the base of a cloud.


SST

SST (countable and uncountable, plural SSTs)

(meteorology) Initialism of sea surface temperature.


downsloping

Downsloping creates an environment that is far less conducive to thunderstorms[…]

2005, Matthew Miller, Weird, Wild & Unpredictable: An Illustrated History of East Tennessee Weather, page 42:

While dewpoints are still fairly elevated, due to west downsloping dewpoints are about 2-4 degrees lower than yesterday in the mid to upper 60s.

2020 NWS Boston 1103 AM EDT forecast discussion

(meteorology) Air descending a slope, resulting in adiabatic warming and reduction in relative humidity.


heat index

heat index (plural heat indexes or heat indices)

heat indexes (plural)
heat indices (plural)

(US, meteorology) A figure used by American meteorologists to describe the apparent heat felt by a person as the result of a combination of temperature and humidity.

temperatura de xafogor

figure used to describe the apparent heat felt by a person


SHRA

(US, meteorology) Abbreviation of rain showers.


BKN

(meteorology) Abbreviation of broken (as in cloud cover).


SCT

(meteorology) Abbreviation of scattered.


SLD

supercooled large droplet
supercooled large droplet#English

(meteorology, aviation) Initialism of supercooled large droplet.


spaghetti chart

spaghetti chart (plural spaghetti charts)


spaghetti model

spaghetti model (plural spaghetti models)

(meteorology) An illustration showing the various projected paths of a weather phenomenon (typically a tropical storm) created by different computer models.


isobarometric

isobarometric curve

isobarometric lines, i.e. isobars

(archaic, meteorology) Indicating equal barometric pressure.


undulatus

undulatus asperatus cloud
undulatus asperatus cloud#English

(meteorology) Ellipsis of undulatus asperatus cloud.


blue jet

blue jets (plural)
blue-jet (alternative)
bluejet (alternative)

Mysterious bluejets can be seen with the naked eye from the ground, but they are rare and difficult to spot.

1999, Patricia Barnes-Svarney, Thomas E. Svarney, Skies of fury: weather weirdness around the world, Simon and Schuster, page 100:

(astronomy, meteorology) An upper atmospheric optical phenomenon associated with thunderstorms, a rapidly expanding disk-shaped region of luminosity, lasting less than a thousandth of a second, which occurs high above energetic cloud-to-ground lightning of positive or negative polarity.


blue starter

Blue starters were first observed in 1994.

2007, Vladimir A. Rakov, Martin A. Uman, Lightning: Physics and Effects, Cambridge University Press, page 483:

(meteorology) A rapidly expanding disc-shaped region of luminosity, lasting less than a thousandth of a second, seen high above energetic lightning associated with hail-producing regions of thunderstorms, reaching up no higher than about twelve miles altitude.


transient luminous event

transient luminous event (plural transient luminous events)

Transient luminous events can be another source of ionization in the upper atmosphere.

2010, Rafael Escribano Torres, Isabel Tanarro Onrubiay, Spectroscopy of the atmospheres, CSIC, page 34:

During World War II (and probably before), high flying pilots were reported to have observed unexplained aerial phenomena (UAP), often now called transient luminous events (TLE’s), particularly in the vicinity of thunderstorms.

2012, Don Lipman, “Red sprites, blue jets, and elves What are these mysterious, elusive phenomena?”, in The Washington Post:

Known as Transient Luminous Events (TLEs), these unusual features were first spotted by accident in 1989.

2018, Mary Halton, “Hunting mystery giant lightning from space”, in BBC News:

(astronomy, meteorology, aviation) Any of a variety of upper atmospheric optical phenomena associated with thunderstorms.


sprite halo

sprite halo (plural sprite halos or sprite haloes)

sprite halos (plural)
sprite haloes (plural)

In lhe: early days of LLTV monitoring it was common to observe an apparent elve followed by a sprite, sometimes called a "sprelve." While elves do indeed precede some sprites, the "sprelve" in most cases, was found to represent a "sprite halo."

2006, Martin Füllekrug, Eugene A. Mareev, Michael J. Rycroft, Sprites, elves and intense lightning discharges, page 37:

(astronomy, meteorology) An upper-atmospheric optical phenomenon associated with thunderstorms, a diffuse disk-shaped glow that precedes a sprite and propagates downward.


sprelve

In the early days of LLTV monitoring it was common to observe an apparent elve followed by a sprite, sometimes called a "sprelve." While elves do indeed precede some sprites, the "sprelve" in most cases, was found to represent a "sprite halo."

(astronomy, meteorology) An upper atmospheric optical phenomena associated with thunderstorms, in which an elve is immediately followed by a sprite.


upward lightning

upward lightning (countable and uncountable, plural upward lightnings)

(astronomy, meteorology) An upper-atmospheric optical phenomenon associated with thunderstorms, in which the lightning bolt projects straight into the upper atmosphere.


red sprite

Red sprites flash high above thunderstorm clouds.

1999, Patricia Barnes-Svarney, Thomas E. Svarney, Skies of fury: weather weirdness around the world, Simon and Schuster, page 99:

(astronomy, meteorology) An upper atmospheric optical phenomena associated with thunderstorms, a large but weak luminous flash that appears directly above an active thunderstorm system and is coincident with a powerful positive cloud-to-ground lightning strike.


gigantic jet

Gigantic jets appear to provide an electrical connection between cloud tops and the ionosphere.

2009, Michael C. Kelley, The earth's ionosphere: plasma physics and electrodynamics, Academic Press, page 364:

(astronomy, meteorology) An upper atmospheric optical phenomena associated with thunderstorms, a carrot-shaped red sprite that propagates upward from the core of an oceanic thunderstorm.


recurvature

recurvature (countable and uncountable, plural recurvatures)

(meteorology) Part of the motion of a tropical cyclone, where its track becomes strongly poleward with an easterly component.


cloud street

(meteorology) Long rolls of counterrotating air that are oriented approximately parallel to the ground in the planetary boundary layer.


SIGMET

Abbreviation of Significant Meteorological Information.

(meteorology, aviation) A weather advisory concerning the safety of all aircraft.


meltemi

from Greek μελτέμι (meltémi), from Turkish meltem

(meteorology) A strong, dry, northerly, seasonal wind in the Aegean sea; etesian wind.


temperature inversion

temperature inversion (plural temperature inversions)

Temperature inversions can occur in perfectly clear skies. Samford said such an inversion was present in the Washington area early last Sunday, when up to a dozen unidentified flying objects appeared on radar screens both at Washington national airport and nearby Andrews air base.

1952 July 30, Vern Haugland (Associated Press), "Air Force Says Saucers No Menace to US", Ludington Daily News (Michigan, USA), p. 1 (Retrieved 21 June 2012)

It's possible that a temperature inversion—a layer of warm air lying on top of a layer of cold air—is causing the sounds of the sonic booms to be carried inland, he said.

1993 March 6, Linda Hetsel, “Jets over Gulf may have caused booms”, in Victoria Advocate, Texas, USA, retrieved 2012-06-21, page 12A:

Bottled up by a temperature inversion, the gunk grew so dense that the Utah Division of Air Quality imposed the season's first "red" no-burn restrictions,

2005 Dec. 13, Joe Bauman, "Wasatch's gray skies trigger a red advisory, but a storm front today could ease air pollution, Deseret News (Utah, USA) (Retrieved 21 June 2012)

(meteorology) An atmospheric condition in which a cooler layer of air lies below a warmer layer of air that functions as a "ceiling" for the cooler layer, interfering with normal atmospheric circulation and trapping pollutants.


rain shower

rain showers (plural)
rainshower (alternative)
rain-shower (alternative)

From Middle English, from Old English reġnscūr, from Proto-Germanic *regnaskūrō. Equivalent to rain + shower. Cognate with Saterland Frisian Rienskuur and Icelandic regnskúr.

(weather) A short, mild period of rainfall.


absolute pressure

atmospheric pressure
atmospheric pressure

(physics, meteorology) Total pressure in a fluid equivalent to the sum of the gage and the atmospheric pressures.

presión absoluta

pressure caused by weight of the atmosphere


absorption hygrometer

absorption hygrometer (plural absorption hygrometers)

/æbˈsɔɹp.ʃn̩ haɪˈɡɹɑm.ɪ.tɚ/

/æbˈzɔɹp.ʃn̩ haɪˈɡɹɑm.ɪ.tɚ/

/əbˈzɔɹp.ʃn̩ haɪˈɡɹɑm.ɪ.tɚ/

/əbˈsɔɹp.ʃn̩ haɪˈɡɹɑm.ɪ.tɚ/

(meteorology) An instrument using organic material to measure the atmospheric moisture level.


MSL

The company shard specific data from today’s flight on social media, revealing that the New Shepard capsule that carried Katy Perry, Gayle King and their crewmates to space hit 346,802 feet above ground level (AGL) and 350,449 above mean sea level (MSL).

2025 April 14, Jackie Wattles, Ashley Strickland and Taylor Nicioli, “Blue Origin launches star-studded crew on space tourism rocket”, in CNN:

(aviation, meteorology, oceanography) Initialism of mean sea level.


hail shaft

hail shafts (plural)
hailshaft (alternative)
hail-shaft (alternative)

(weather) a region of intense rain and hail accompanied by a strong downdraft


(aeronautics, NASA, meteorology) Initialism of Hurricane and Severe Storm Sentinel, a project launched in August 2012 to observe hurricanes.


snowicane

snowicanes (plural)
snowricane (alternative)
snow-ricane (alternative)

The giant storm — dubbed a “Snowicane” — was coming up the East Coast like a steamroller in overdrive.

1993, American Philatelic Association, The American philatelist:

The snowicane that had raged for three days and three nights had left him as bad off as the pheasants, and it wasn't any easier for him to allay his hunger pains in the vast wasteland of snow than it was for them.

… it’s nice to think about baseball in the calm before the snow-ricane we are about to allegedly have.

It's pretty apparent that Craig the weatherman was not in my Brooklyn neighborhood because we had a full-blown snowicane.

2011, Todd Starnes, Dispatches from Bitter America:

(meteorology) A hurricane or other such tropical storm which precipitates snow.


TLE

TLE (countable and uncountable, plural TLEs)

transient luminous event
transient luminous event#English

(meteorology, aviation) Initialism of transient luminous event.


1-h TL FM

(US, meteorology) Initialism of one-hour timelag fuel moisture.


skew-T log-P diagram

skew-T log-P diagram (plural skew-T log-P diagrams)

The chart contains a skewed temperature axis (Skew-T) and a logarithmic pressure axis (Log-P).

(meteorology) A thermodynamic diagram used for weather forecasting and atmospheric analysis.


horse latitudes

Various theories; probably from a sailors' ritual of parading a straw-stuffed effigy of a horse around the deck before throwing it overboard.

horse-latitudes (alternative)
Horse Latitudes (alternative)

At the equator, an immense mist seems permanently to encircle the globe. It is known as the cloud-ring. The function of the cloud-ring is to temper the heat of the tropics. . . . These are what are called horse latitudes. It was here that navigators of bygone ages were accustomed to cast their horses into the sea to lighten the ship in stormy weather.

1866, Victor Hugo, chapter 6, in W. Moy Thomas, transl., Toilers of the Sea:

The north boundary of Zone A is a belt of high barometric pressure known to many generations of seafaring men as the "Horse Latitudes." Here air currents are divergent and there is relatively low humidity.

1945 May, “What is Weather?”, in Flying Magazine, volume 36, number 5, page 31:

The 27,000-mile course starts in November in the Bay of Biscay on the coast of France; points south through the horse latitudes and doldrums, past Africa to the bottom of the world; rounds Cape Horn; then turns north to home.

1999 August 15, Lance Morrow, “Captains Courageous”, in Time:

The captain used the idle Horse Latitudes to train and prepare the remainder of the crew.

2011, Dominic Smith, Bright and Distant Shores, →ISBN, page 125:

(informal, geography, meteorology) The warm, subtropical bands which encircle the globe between approximately 30 and 35 degrees both north and south of the Equator, characterized by high atmospheric pressure and dry variable winds ranging from calm to light.

зони на безветрие

warm, dry subtropical bands encircling the globe


Tornado Alley

/ˌtɔː(ɹ)ˈneɪdəʊ ˈælɪ/

From tornado + alley. Coined in 1952 by U.S. Air Force meteorologists Ernest J. Fawbush and Robert C. Miller.

(US, meteorology) A region of the United States, located in the middle of the country, where tornadoes are particularly frequent and intense.


stormtrack

stormtracks (plural)
storm-track (alternative)
storm track (alternative)

(weather, meteorology) The path traversed by the centre of a cyclonic storm.


turbopause

(meteorology) The altitude in the Earth's atmosphere below which turbulent mixing dominates, at about 60 miles or 100 km, which separates the heterosphere from the homosphere.


PSC

PSC (countable and uncountable, plural PSCs)

(meteorology) Initialism of polar stratospheric cloud.


thundersquall

“And pray, sir,” said he, looking thundersqualls at me, “ where did you learn them?”

1855, Thomas Chandler Haliburton, Nature and Human Nature, Stringer and Townsend, page 279:

Then Dick began a suit. for the recovery of wages due him, which Podlong resisted on the ground that Dick had broken his contract, and subjected him to great loss and inconvenience by striking work in the midst of a thundersquall in the hayfield.

1863, John Townsend Trowbridge, Woodie Thorpe's Pilgrimage and Other Stories, Boston, Lee and Shepard, page 228:

The 25th brought yet more storms and a violent thundersquall in Norfolk caused a great deal of damage in Stratton Strawless?

(rare, nautical, meteorology) A squall accompanied by thunder.


glaciogenic

en-adj

glaciogenic (comparative more glaciogenic, superlative most glaciogenic)

more glaciogenic (comparative)
most glaciogenic (superlative)

(meteorology) That seed ice crystals in the upper atmosphere.


isophane

en-noun

isophane (countable and uncountable, plural isophanes)

From iso- (same) + -phane (“appearing”).

(countable, meteorology) A line drawn on a map through points where a given seasonal biological event occurs on the same date.


roaring forties

Its official demarcation is forty degrees south latitude. It includes the latitudes sailors long-ago nicknamed the roaring forties, the furious fifties, and the screaming sixties. It's an area of almost constant high wind and frequent gales, often exceeding hurricane strength.

1998, Derek Lundy, chapter 1, in Godforsaken Sea: Racing the World's Most Dangerous Waters, page 5:

(geography, meteorology) The area of the earth between 40 and 50 degrees south, prone to gale-force westerly winds.


superhurricane

LL-Q1860 (eng)-Flame, not lame-superhurricane.wav


Kelvin wave

Named after Lord Kelvin, the discoverer (1879).

Geophysicists have leaned on a mathematical explanation for equatorial Kelvin waves since the 1960s, but for some, that explanation wasn’t entirely satisfying.

2023 July 18, Katie McCormick, “How Quantum Physics Describes Earth’s Weather Patterns”, in Quanta Magazine:

(meteorology, oceanography) A non-dispersive wave in the ocean or atmosphere that balances the Earth's Coriolis force against a topographic boundary such as a coastline, or a waveguide such as the equator.


rainband

(meteorology) An elongated cloud and precipitation structure associated with an area of rainfall.

The spiralling bands of cloud and precipitation that make up the bulk of most tropical cyclones.


roll cloud

They usually appear to be "rolling" about a horizontal axis.

(meteorology) A low, horizontal, tube-shaped, and relatively rare type of arcus cloud, differing from shelf clouds by being completely detached from other cloud features.


windmeter

(meteorology) An instrument for measuring and recording the speed of the wind.


sand pillar

Near-synonym: dust devil

(meteorology) A whirling, columnar vortex of sand occasionally seen in desert regions.


dry line

(meteorology) An imaginary line across a continent that separates moist air from an eastern body of water and dry desert air from the west.


weather satellite

weather satellite (plural weather satellites)

(meteorology) A type of satellite that is primarily used to monitor the weather and climate of the Earth.


frontogenetic

In studying frontogenetic processes in the lower boundary layer, which will maintain or strengthen the horizontal temperature gradient across the surface front the question arises as to how important frictional effects will be.

1989, Contributions to Atmospheric Physics:

That definition of frontogenesis differs somewhat from the familiar Petterssen "frontogenetic factor," which we have termed "horizontal accumulation" and which does not consider adequately the vertical continuity of the frontal zone.

2003, Walter J. Saucier, Principles of Meteorological Analysis, →ISBN, page 367:

In some winters, however, the Eurasian snow-cover ultimately becomes firmly established as far west as the Harz Mountains in northern Germany, or even as far as the British Isles, and the frontogenetic belt is near this boundary, orientated from NW to Se or from N to S.

2013, H. H. Lamb, Weather, Climate and Human Affairs, →ISBN, page 271:

(meteorology) Tending to maintain or intensify horizontal temperature gradients, which are associated with enhanced precipitation in large scale storm systems.


isoecho

(meteorology, aviation) A line on a map joining points of equal radar reflectivity.


cirro-

From cirrus (“cloud-type”) and Latin cirrus (“fringe”).

(meteorology) related to clouds of high étage


alto-

(meteorology) relating to clouds of middle étage


atmospheric river

atmospheric river (plural atmospheric rivers)

A sequence of atmospheric rivers will bring heavy rainfall and snow to the Western U.S. and Canada over the next week.

2024 January 26, Judson Jones, “More Atmospheric Rivers Are on the Way. Here’s What the West Can Expect.”, in The New York Times, →ISSN:

(meteorology) A narrow and long band of atmospheric moisture that transports a lot of water vapour, originating from the tropics, in a manner superficially similar to how a terrestrial river transports water.


hailfall

hailfall (countable and uncountable, plural hailfalls)

(meteorology) An instance of hail falling.

(meteorology) The amount of hail that falls on one occasion.


antimonsoon

(meteorology) The upper, contrary-moving current of the atmosphere over a monsoon.


wintry mix

(US, meteorology) A mixture of freezing rain, ice pellets, and snow.


hydroclimate

(meteorology) The part of a climate influenced by water


weather bomb

(meteorology) A large storm that evolves with little warning, usually as a result of a sudden drop in barometric pressure.


explosive cyclogenesis

explosive cyclogenesis (countable and uncountable, plural explosive cyclogeneses)

From explosive + cyclogenesis. From being the explosive (-ly rapid) generation of an extratropical cyclonic storm.

1985, SJ Colucci. Journal of the atmospheric sciences, Volume 42, number 24, page 2701, Explosive cyclogenesis and large-scale circulation changes: Implications for atmospheric blocking

1986, Frederick Sanders, Monthly Weather Review, Volume 114, page 1781, Explosive Cyclogenesis in the West-Central North Atlantic Ocean, 1981–84. Part I: Composite Structure and Mean Behavior.

2000, John R. Gyakum and Richard E. Danielson, Monthly Weather Review, Volume 128, page 851, Analysis of Meteorological Precursors to Ordinary and Explosive Cyclogenesis in the Western North Pacific.

(meteorology) A decline in the barometric pressure of twenty-four millibars over a twenty-four hour period at or north of sixty-degrees latitude.

爆発性低気圧発生

ばくはつせい ていきあつ はっせい


meteorological bomb

meteorological bomb (plural meteorological bombs)


paleotempestological

(weather) Relating to paleotempestology.


freeze-up

(seasons, time) The start of the time when surface waters are frozen over.


earthstorm

This earthquake was an earthstorm. Hills were waves, and houses cast adrift were wrecked on them.

1931, Charles Fort, “Lo!”, in The Complete Books of Charles Fort, Dover Publications, published 1974, →ISBN, page 768:

There is an earthstorm, disks of rock careering skyward, buffeting the train.

2004, China Miéville, Iron Council, Del Rey, →ISBN:

It had come from the west, the shock wave from some almighty earthstorm in lost America, rolling clear across the Atlantic before breaking over Thursday Island. It had smashed down buildings, and sunk the ships whose dead masts could still be seen jutting sadly from the water in the harbor.

2010, Philip Reeve, Fever Crumb: A Web of Air, Scholastic, →ISBN:

(seismology, weather, fantasy) An extremely powerful earthquake; a storm involving earth or rock blowing through the air.


Madden-Julian oscillation

the Madden-Julian oscillation (canonical)

Discovered in 1971 by Roland Madden and Paul Julian of the American National Center for Atmospheric Research.

(meteorology) The largest element of the intraseasonal variability in the tropical atmosphere: a large-scale coupling between atmospheric circulation and tropical deep convection, manifesting itself most clearly as anomalous rainfall.


relative pressure

(physics, meteorology) Synonym of gauge pressure.


gauge pressure

(physics, meteorology) The absolute pressure minus the atmospheric pressure.

presión manométrica

the absolute pressure minus the atmospheric pressure


GCM

(meteorology, climatology) Initialism of General Circulation Model.


wind force

wind force (countable and uncountable, plural wind forces)

(meteorology) the strength of the wind. The Beaufort scale was devised to classify wind forces of various strengths.


geocoronium

From geo- + corona + -ium, coined by Alfred Wegener in 1911.

(geophysics, meteorology, obsolete) A hypothetical gaseous chemical element proposed to explain certain spectroscopic lines, and the green glow, found in the polar aurorae, that was later found to be explained by singly-ionized oxygen.


red box

gray-box testing
red box
white box (software engineering)

See also: severe thunderstorm watch

(informal, US, meteorology) A "tornado watch" notification, indicating that conditions might lead to a tornado though none has yet been sighted.


dark flight

(astronomy, meteorology, geology) The portion of the flight of a meteor, after its incandescent fireball phase, when the space rock has cooled down and slowed down, so that it is no longer glowing, but still in flight, and yet to crash onto the ground.


wedge tornado

(meteorology) A tornado that is at least as wide as it is tall, on the ground level as well as on the cloud base, looking very massive, often opposed to a rope tornado.


super greenhouse gas

super greenhouse gas (plural super greenhouse gases)

(climate) Any greenhouse gas with a greenhouse effect that is several orders of magnitude stronger than that of carbon dioxide.


AIRMET

(meteorology, aviation) Abbreviation of airman's meteorological advisory.


Spanish plume

(meteorology) A weather pattern where hot air from the Iberian Peninsula flows towards Northern Europe, often causing high temperatures and also severe thunderstorms.


sudden stratospheric warming

sudden stratospheric warming (countable and uncountable, plural sudden stratospheric warmings)

(meteorology) A weather phenomenon where the polar vortex breaks down, causing a sudden temperature increase in the stratosphere of 50 kelvin or more.


North Atlantic Oscillation

North Atlantic Oscillation (plural North Atlantic Oscillations)

(meteorology) The difference in pressure between the Azores High and the Icelandic Low, which changes periodically and controls the strength of the Westerlies. Usually abbreviated NAO.


Azores High

(meteorology) A center of high atmospheric pressure that is always present around the Azores and plays an important role for the weather in Europe.


Icelandic Low

(meteorology) A center of low atmospheric pressure that is always present around Iceland and plays an important role for the weather in Europe.


Stevenson screen

Stevenson screen (plural Stevenson screens)

Designed by Thomas Stevenson (1818–1887), British civil engineer.

(meteorology) A standardized shelter that holds meteorological instruments and protects them from directly being influenced by wind, sunlight and rain.


isallobar

Seasonal variations of atmospheric pressure are illustrated by the isallobaric chart […] which gives the differences between mean pressure in July–August, and in January–February. The position of the isallobars on this chart is largely indicative of the role of monsoonal factors […]

1965, L. V. Kool', “The pressure field of the Atlantic trade-wind belt and its changes with height”, in Oceanology, volume 5, numbers 4-6, page 35:

Successive values of pressure provide figures for the barometric tendency, permitting the plotting of isallobars […] This is called tendency analysis.

1977, Edward Linacre, John E. Hobbs, Ann McGrath, The Australian climatic environment, page 153:

If your barometer has dropped 0.05 of an inch in the last three hours, you are on the -0.05 isallobar.

1977, Blair & Ketchum's Country Journal, volume 4, page 27:

(meteorology) A line joining points of equal pressure change during a specific time interval, especially over three hours.


SPECI

(aviation, meteorology) The aviation special weather report; a specially encoded weather observation report.


spring melt

(meteorology) The time of the year, generally in the early spring, when the snowpack accumulated during the winter melts.


trowal

Mid-tropospheric frontogenesis occurred to the northwest of the negative EPV region as the trowal airstream became confluent with the cold air to the north of the cyclone.

2010, William R. Cotton, Storm and Cloud Dynamics, page 564:

(meteorology) The projection on the Earth's surface of the trough of warm air aloft formed during the occlusion process of the depression.


Saffir-Simpson scale

Developed in 1971 by civil engineer Herbert Saffir and meteorologist Robert Simpson.

(meteorology) A scale used to classify hurricanes by the intensity of their sustained winds, and thus the level of damage they might cause.


Hovmöller diagram

Hovmöller diagram (plural Hovmöller diagrams)

Named after Ernest Aabo Hovmöller, a Danish meteorologist.

(meteorology) A depiction of changes in the atmosphere, mapping longitude or latitude to the x-axis and time to the y-axis.


anafront

(meteorology) A warm or cold front at which there is upward movement of the warm-sector air above the cold-sector air, commonly producing clouds and precipitation on the cool side of the boundary.


katafront

From kata- + front, coined by T. Bergeron.

(meteorology) A weak frontal condition in which warm-sector air sinks relative to colder air.


frontogenetical

From frontogenetic + -al, ultimately fronto- + genetic + -al.

Therefore if Q and Vp0 are in the same direction, the frontogenetical function is positive and there is a thermally direct circulation, and vice versa (Hoskins and Pedder, 1980).

1986, Peter S. Ray, Mesoscale Meteorology and Forecasting, page 186:


subcloud

CQE theories that diagnose ITCZ location based on the subcloud moist static energy maximum are shown to have large biases; accounting for convective entrainment of dry air by using a lower-tropospheric mean moist static energy provides a more correct diagnosis of ITCZ location.

2016, Ravi Shekhar, William R. Boos, “Improving Energy-Based Estimates of Monsoon Location in the Presence of Proximal Deserts”, in arXiv:

(meteorology) An atmospheric object smaller than a cloud


subcloud

en-adj

subcloud (comparative more subcloud, superlative most subcloud)

more subcloud (comparative)
most subcloud (superlative)

(meteorology) The region (or layer) below the base of a cloud.


barometric pressure

en-noun

barometric pressure (countable and uncountable, plural barometric pressures)

(physics, meteorology) The downward force of the atmosphere onto the Earth; at sea level a unit of air pressure is one atmosphere, air pressure decreases as the altitude increases and is measured in millibars or pascals.


superbolt

superbolts (plural)
super bolt (alternative)
super-bolt (alternative)

LL-Q1860 (eng)-Flame, not lame-superbolt.wav

A typical lightning bolt has an optical power of about 1 billion watts. The superbolt flashes radiate 100 billion to 10 trillion (10¹¹)-(10¹³) watts. They are quite rare.

1979, Kendrick Frazier, The Violent Face of Nature: Severe Phenomena and Natural Disasters, Morrow, →ISBN, page 97:

This low lightning rate is insufficient to affect the global NOx production, however it may cause local enhancement near Japan where most superbolts occur.

1981, Marta Kowalczyk, Lightning as a source of NOx in the troposphere:

In rare cases a positively charged giant 'superbolt' may discharge from the forward (or rear) anvil cloud to the negatively charged ground ahead of (or behind) the thunderstorm base.

2015, Derek M. Elsom, Lightning: Nature and Culture:

(meteorology, rare) A rare form of lightning where the bolt is much stronger (such as 100x) and lasts much longer (such as 5x) than the usual forms of lightning.


maumy

en-adj

maumy (comparative more maumy, superlative most maumy)

more maumy (comparative)
most maumy (superlative)


European windstorm

en-noun

European windstorm (plural European windstorms)

From January 15–19, 2007, a cyclone over the Netherlands generated a “European windstorm” with high sustained winds and gusts up to 202 km/h.

2016, Kristi L. Koenig, Koenig and Schultz's Disaster Medicine:

(meteorology) The strongest kind of extratropical cyclone occurring across the continent of Europe, associated with areas of low atmospheric pressure.


ageostrophic

It might sound puzzling that the ageostrophic geopotential (or the ageostrophic pressure in z-coordinate) has no impact on the evolution of the vorticity of a quasi-geostrophic disturbance and yet it affects the perturbation kinetic energetics (not globally but locally).

2004, Zhu Xun, Li Xiaofan, Cai Ming, Observation, Theory And Modeling Of Atmospheric Variability, →ISBN, page 13:

Note that the ageostrophic wind has both a divergent and a nondivergent part.

2004, James R. Holton, An Introduction to Dynamic Meteorology - Volume 1, →ISBN, page 179:

Ageostrophic circulations play a significant role in the kinematics and dynamics of a variety of synoptic- and mesoscale weather systems found within extratropical baroclinic wave regimes.

2015, Melyvn Shapiro, The Life Cycles of Extratropical Cyclones, →ISBN, page 239:


bomb cyclone

From bomb + cyclone, referring to the extreme rapidity of the storm's development.

It has been suggested that some east coast bomb cyclones form by this process (Shapiro and Keyser, 1990).

1992, Peter Jon Pokrandt, A three-dimensional, nonhydrostatic investigation of warm core cyclogenesis at high latitude, University of Wisconsin--Madison, page 1:

c. 1999, Monthly Weather Review, Volume 128, Issues 1-4, American Meteorological Society, page 403,
In a compositing study of bomb cyclones, Manobianco (1989) found a prominent localized VM upstream from the developing surface cyclone.

However, the bomb cyclones’ size and depth are typically larger in the EM^([Eastern Mediterranean]) than in its western part (Kouroutzoglou et al., 2011).

2012, Piero Lionello, editor, The Climate of the Mediterranean Region: From the Past to the Future, Elsevier, page 316:

The winter storm that forecasters dubbed Elliott intensified into a bomb cyclone near the Great Lakes on Friday, bringing high winds and blizzard conditions from the Northern Plains to western and upstate New York, along with life-threatening flooding, flash-freezing and travel chaos as it went.

2022 December 23, Jon Henley, Edward Helmore, Maya Yang, “Gigantic US winter storm leaves millions without power and cancels holiday plans”, in The Guardian:

(meteorology) A type of extratropical cyclone characterized by high winds, a high level of precipitation, and rapid development.


spray bow

spray bows (plural)
spraybow (alternative)

From spray + bow, by analogy with rainbow.

M. Kohl gives us some graphic descriptions, especially of the scene behind the Horse-shoe Fall, and of a lunar spray-bow on the American, for which we must refer to his book.

1861 January, anonymous author, The Westminster Review, Canada, page 34:

Now that level place, or bench-table went up to the very gushing and green bow of the water, so Ralph took Ursula's hand and led her along, she going a little after him, till he was close to the Well, and stood amidst the spray-bow thereof, so that he looked verily like one of the painted angels on the choir wall of St. Laurence of Upmeads.

1896, William Morris, The Well at the World's End: A Tale, Volume 2, page 94:

It would need a long essay in optics, I imagine, to explain why the spray-bow was very blue and the cloud-bow quite without this colour ; for rainbows differ more in their attributes than most observers recognise.

1935, Sir William Beach Thomas, Village England, page 95:

I sometimes amuse myself by making spray bows with a plant spray.

2002, John Naylor, Out of the Blue: A 24-Hour Skywatcher's Guide, page 106:

(meteorology) A rainbow formed from water spray, especially that which emanates from a waterfall.


red flag warning

red flag warning (plural red flag warnings)

During red flag warnings, firefighting agencies will alter their staffing and equipment resources dramatically to accommodate the increased forecast risk.

2014, Jeffery Sims, The No-Nonsense Guide to Heat Wave, Drought, & Hot Weather Safety:

(meteorology, US) A warning issued by the United States National Weather Service that conditions are ideal for wildfires.


eolation

Likely from Eolus (“god of wind”), Aeolian (“relating to Eolus”), or aeolo- (“of woodwind instruments”), all via Latin Aeolus from Ancient Greek Αἴολος (Aíolos), plus -ation, a suffix denoting a process or the result of a process.

Eolian erosion, wind scour, or eolation, must ever grow in effectiveness as the history of our globe goes on and erosion lasts.

1910, Charles R. Keyes, “Deflation and the relative efficiency of erosional processes under conditions of aridity”, in Bulletin of the Geological Society of America, page 566:

(geology, meteorology) Any effect of wind on land.


tornadogenesis

(meteorology) The process by which a tornado forms


meteotsunami

These surface waves are associated with two ma- jor sources of forcing: seismic activity (tsunamis) and atmospheric disturbances (meteotsunami).

1998 June 15, S Monserrat, “On the reconstruction of the transfer function for atmospherically generated seiches”, in Geophysical Research Letters, volume 25, number 12, page 2197:

(oceanography, meteorology) A tsunami-like wave of meteorological origin.


stratocumuliform

Latin stratus (“layer”) cumulus (“heap”) + -iform

(meteorology, of clouds) Resembling cumulus but with extensive horizontal development.


surface analysis

surface analysis (countable and uncountable, plural surface analyses)

From surface (“outside hull”) + analysis.

(meteorology) See surface weather analysis.


medicane

Mediterranean tropical-like storms (the “medicane” term has been proposed for these storms) evolve under significantly different environmental conditions compared with the tropical ones.

[2007 January 15, L. Fita, “Analysis of the environments of seven Mediterranean tropical-like storms using an axisymmetric, nonhydrostatic, cloud resolving model”, in Natural Hazards and Earth System Science, volume 7, page 41:

The methodology is presently transferred to the analysis and projection of North Pacific polar low statistics and that of medicanes, vigorous below synopticscale cyclones in the Mediterranean (The word medicane is a hybrid of Mediterranean and hurricane).

2013, A. Surjalal Sharma, Extreme Events and Natural Hazards: The Complexity Perspective:

Thus, it is essential to study medicanes and calibrate the numerical weather prediction models in order to simulate them adequately.

2016, Theodore Karacostas, Perspectives on Atmospheric Sciences, page 115:

After pounding parts of western and central Greece meteorologists have predicted a rare Mediterranean hurricane-like storm, or medicane, is headed south towards the island of Crete.

2020 September 19, Helena Smith, “Medicane Ianos turns towards Crete after sweeping across Greece”, in The Guardian, →ISSN:

The flash flood that has killed thousands of people in Libya this week followed a “medicane”, a rare but destructive weather phenomenon that scientists believe will intensify in a warming world.

2023 September 15, “What are medicanes? The ‘supercharged’ Mediterranean storms that could become more frequent”, in The Guardian, sourced from Agence France-Presse, →ISSN:

(meteorology, informal) A hurricane-like storm that forms in the Mediterranean Sea.


rope tornado

From rope + tornado, from the thin, ropelike appearance of the funnel cloud.

(meteorology) A tornado that is much longer than it is wide, and often sinuous, often opposed to a wedge tornado.


tornadic waterspout

tornadic waterspout (plural tornadic waterspouts)

(meteorology) A true tornado (associated with a thunderstorm) forming over a body of water.


MOGREPS

(meteorology) Acronym of Met Office global and regional ensemble prediction system.


near space

near-space (alternative)
nearspace (alternative)

A region of the Earth's (or another planet's) atmosphere or exosphere which is near outer space:

(meteorology) The mesosphere and lower thermosphere.


teleconnected

(meteorology) connected by a teleconnection


pluviothermic

(meteorology) Relating to rainfall and temperature


roll cumulus

(meteorology) A form of stratocumulus with parallel lines of dense cloud.


Colorado clipper

Colorado clipper (plural Colorado clippers)

Blend of Colorado low + Alberta clipper.
From being a class of storms originating in Colorado that move like Alberta clippers.

(Canada, meteorology) Synonym of Colorado low.


Colorado low

From Colorado + low.
From being a low pressure system originating in the uploads of Colorado.

(meteorology) A fast moving high precipitation winter storm system originating out of Colorado, and traveling east across the United States, dumping much snow on the Great Plains and the Midwest.

Alberta clipper

a similar class of storm systems in Canada


tempestology

Reanalyses combine observations with a short forecast from a general circulation model (GCM) to produce gridded datasets, constrained by observations, with regular output intervals, and can act as a bridge between the observations of TCs and simulated tempestology.

2017, K Hodges, “How well are tropical cyclones represented in reanalysis datasets?”, in Journal of Climate:

(meteorology, rare) The study of cyclones, hurricanes and similar extreme events


flash flooding

Just before 1300, a train driver reported fast-flowing water near Pontrilas. Flash flooding removed ballast, leaving sections of track suspended in the air.

2019 November 6, “Flash floods close Marches Line in Wales”, in Rail, page 13:

Flooding occurs in areas where the ground is unable to absorb all of the water, according to forecasters, who explained that flash flooding can also be caused by mudslides or breaks in dams or levees.

2021 July 18, Neil Vigdor, “What Is Flash Flooding, and How Can You Avoid It?”, in The New York Times, →ISSN:

(meteorology) Flooding that occurs during a flash flood.


ground frost

(meteorology) The condition of air temperature dropping below the freezing point at or near ground level.


Cold Sunday

(meteorology, historical) Sunday, January 17, 1982, when unprecedentedly cold air swept down from Canada and plunged temperatures across much of the United States far below existing all-time record lows.


weather radar

weather radar (countable and uncountable, plural weather radars)

(meteorology) A type of radar used to locate precipitation, calculate its motion, and estimate its type.


epedaphic

(meteorology) Relating to atmospheric conditions


super outbreak

From super + outbreak (“tornado outbreak”). Coined by Dr. Tetsuya Theordore "Ted" Fujita in 1974, after a then-recent outbreak of tornadoes that was the largest known to have occurred.

Cycloidal ground marks were replete in the super-outbreak. Figure 3.35 illustrates the small cycloidal swaths of the Anchor, Illinois, tornado and the giant cycloidal swaths of the Homer Lake, Indiana, tornado.

1983, Robert F. Abbey Jr., T. Theodore Fujita, “Tornadoes: The Tornado Outbreak of 3-4 April 1974”, in Edwin Kessler, editor, The Thunderstorm in Human Affairs, page 62:

The tornado Super Outbreak of 2011 was the largest in US history. From April 26 to April 28, more than 300 tornadoes spun across the eastern United States.

2012, Kristen Rajczak, Terrifying Tornadoes, page 22:

In the following months, careful analysis of all the damage led Dr. Fujita and other experts to determine that the Xenia tornado was in fact the worst of all the 148 Super Outbreak tornadoes.

2024 November 11 (last accessed), “The Super Outbreak of April 3-4, 1974”, in [US] National Weather Service, archived from the original on 2024-01-03:

tornado outbreak
tornado outbreak#English

(meteorology) A large tornado outbreak involving more than 50 tornadoes within a 24-hour period.


tornado outbreak

tornado outbreak (plural tornado outbreaks)

(meteorology) A collection of tornadoes generated by the same weather system, at around the same or in a short or continuous period of time.


anticorona

From anti- + corona (“optical phenomenon consisting of circles visible around a bright celestial object such as the Sun or the Moon”).

af

(meteorology, optics) The glory optical phenomenon.


CAPE

(meteorology) Convective available potential energy


moist-adiabatic

2020 June 6, "1047 AM EDT Area Forecast Discussion", NWS Boston
Mid level lapse rates remained barely moist-adiabatic, which is not favorable for widespread strong convection.

(meteorology) Describing an adiabatic process where air is fully saturated with water and any temperature change results in evaporation or condensation.


GFS

Global Forecast System
w:Global Forecast System

(meteorology) Initialism of Global Forecast System.


BWER

bounded weak echo region
w:bounded weak echo region

(meteorology) Initialism of bounded weak echo region.


Richardson number

en-noun

Richardson number (plural Richardson numbers)

(fluid mechanics, meteorology) A dimensionless number expressing the ratio of buoyancy to flow shear in a fluid flow.


wall cloud

(meteorology) A localized, persistent, often abrupt lowering from a rain-free base of a thunderstorm.


MLCIN

(meteorology) Mean layer convective inhibition, higher values of which reduce storm formation.