A mackerel sky is a term for clouds made up of rows of

cirrocumulus Cirrocumulus is one of the three main genus types of high-altitude tropospheric clouds, the other two being cirrus and cirrostratus. They usually occur at an altitude of , however they can occur as low as in the arctic and weather reporting sta ...

altocumulus Altocumulus () is a middle-altitude cloud genus that belongs mainly to the physical category, characterized by globular masses or rolls in layers or patchesthe individual elements being larger and darker than those of cirrocumulus and smaller t ...

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

s displaying an undulating, rippling pattern similar in appearance to

fish scales A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scale (zoology), scales, which can also provide effective Underwater camouflage, camouflage through the us ...

; this is caused by high altitude atmospheric waves. Cirrocumulus appears almost exclusively with cirrus some way ahead of a

warm front Warm, WARM, or Warmth may refer to: * A somewhat high temperature; heat * Kindness Music Albums * ''Warm'' (Herb Alpert album), 1969 * ''Warm'' (Jeff Tweedy album), 2018 * ''Warm'' (Johnny Mathis album), 1958, and the title song * ''Warm'' ( ...

and is a reliable forecaster that the weather is about to change. When these high clouds progressively invade the sky and the

barometric pressure Atmospheric pressure, also known as air pressure or barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1,013.2 ...

begins to fall,

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...

associated with the disturbance is likely about 6 to 12 hours away. A thickening and lowering of cirrocumulus into middle-étage

altostratus Altostratus is a middle-altitude cloud genus made up of water droplets, ice crystals, or a mixture of the two. Altostratus clouds are formed when large masses of warm, moist air rise, causing water vapor to condense. Altostratus clouds are usual ...

is a good sign that the warm front or low front has moved closer and it may start raining within less than six hours. The old rhymes "Mackerel sky, not twenty-four hours dry" and " Mares' tails and mackerel scales make lofty ships to carry low sails" both refer to this long-recognized phenomenon. NorwegianMackerelatZionMarketSanDiegoCA

Other phrases in

weather lore Weather lore is the body of informal folklore related to the prediction of the weather and its greater meaning. Much like regular folklore, weather lore is passed down through speech and writing from normal people without the use of external me ...

take mackerel skies as a sign of changeable weather. Examples include "Mackerel sky, mackerel sky. Never long wet and never long dry", and "A dappled sky, like a painted woman, soon changes its face". It is sometimes known as a buttermilk sky, particularly when in the early cirrocumulus stage, in reference to the clouds' "curdled" appearance.

In culture

Peter Paul Rubens Sir Peter Paul Rubens ( ; ; 28 June 1577 – 30 May 1640) was a Flemish painting, Flemish artist and diplomat. He is considered the most influential artist of the Flemish Baroque painting, Flemish Baroque tradition. Rubens' highly charged comp ...

' '' A View of Het Steen in the Early Morning'' (1636) features a depiction of a mackerel sky in art. " Ole Buttermilk Sky" by

Hoagy Carmichael Hoagland Howard "Hoagy" Carmichael (November 22, 1899 – December 27, 1981) was an American musician, composer, songwriter, actor, author and lawyer. Carmichael was one of the most successful Tin Pan Alley songwriters of the 1930s and 1940s, a ...

was nominated for an Academy Award for Best Original Song in 1946.

Gallery

File:Mackerelskybig2.jpg, Mackerel sky over

Erlangen Erlangen (; , ) is a Middle Franconian city in Bavaria, Germany. It is the seat of the administrative district Erlangen-Höchstadt (former administrative district Erlangen), and with 119,810 inhabitants (as of 30 September 2024), it is the smalle ...

, Germany File:Metung-Wharf-Pano,-Vic.jpg, Mackerel sky over

Metung Metung is a town in East Gippsland region of Victoria, Australia. The town is east of the state capital Melbourne and between the larger towns of Bairnsdale and Lakes Entrance. It is on a small peninsula south-east of Bairnsdale, separating ...

, Victoria, Australia File:Altocumulusmackarel.jpg, Mackerel sky over

Heidelberg Heidelberg (; ; ) is the List of cities in Baden-Württemberg by population, fifth-largest city in the States of Germany, German state of Baden-Württemberg, and with a population of about 163,000, of which roughly a quarter consists of studen ...

, Germany File:Peter Paul Rubens - A View of Het Steen in the Early Morning.jpg, Rubens' '' A View of Het Steen in the Early Morning'' File:Altocumulous clouds.jpg, Altocumulus mackerel sky clouds over Burlington, Canada.

References

External links

* {{Cloud types Cumulus

In culture

Gallery

See also

References

External links