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Cloud Gallery

  • 12-05-2008 9:58pm
    Registered Users Posts: 5,033 Snowbie

    *A work in progress. In time, i will include pictures of that type of cloud with descriptions*

    I will use this thread to copy pictures of our clouds we have captured in their different classes/types and forms we have all posted over the last year from Ireland.
    If there are types of clouds that are missing from this forum, i will use external references to class that particular type of cloud.

    We have the 4 main class of cloud:
    Cirro-High level, from 16,500 feet and higher
    Alto-Mid level, from 6,500 feet to 16,500 feet.
    Strato-Low level, from sea level to 6,500 feet.
    Cumuli-Fair weather to convective. From 2000 feet to 30,000+ feet.

    As we have the main class of clouds, there are several types to each class and some even with separate forms.The names are Latin and with every cloud picture, i will give a description and explain each.
    We have witnessed all if not most different clouds in our lifetimes but truly there is so many and with different names. I hope i can give an understanding of each in time.


    Cirrus Radiatus
    Cirrus Intortus
    Cirrus Uncinus
    Cirrostratus Fibratus
    Cirrostratus Nebulosis
    Cirrocumulus Undulatus


    Altostratus Undulatus
    Atocumulus Undulatus
    Altocumulus Mackerel Sky
    Altocumulus Castellanus
    Altocumulus Lenticularis


    Orographic Stratus


    Cumulus Humilis
    Cumulus Mediocris
    Cumulus Congestus
    Cumulonimbus Calvus
    Cumulonimbus Incus
    Cumulonimbus with Pileus
    Cumulonimbus with Mammatus
    Cumulonimbus with Shelf cloud
    Cumulonimbus with Wall cloud
    Cumulonimbus with Funnel cloud.

    Any comments or suggestions to go [thread=2055283298]here[/thread]



  • Cirrus(wisp of hair or curl) clouds are made up of ice crystals instead of water droplets. Upper level winds creates many shapes to cirrus and can also indicate bad weather approaching in advance of weather fronts and moisture present in the atmosphere at high levels.
    The anvil that forms over a cumulonimbus is actually a cirrus cloud.After a storm has completed its life cycle, high level winds will disperse the anvil across the sky producing cirrus clouds.

    Cirrus radiatus is a less common type cirrus which forms in long, parallel lines that seem to radiate from a point in the sky. An extensive deck of radiatus will mostly indicate an approaching front.


    This Pic by gurramok

  • Cirrus Intortus meaning interlaced are cirrus clouds with irregular twists and tangles.


    Pic by Snowbie

    Pic by Mike65

  • Cirrus Uncinus meaning hooked or mared is a familiar and spectacular looking cirrus cloud. It is created when the ice cyrstals descend under gravity into high speed level winds and indicates the presence of the jet stream. The cloud then appears to smear and hook across the sky.



  • Cirrostratus is a thin even layered cloud with no features that covers the sky. When you see a halo around the sun or the moon it is most likely cirrostratus. As with other kinds of cirro clouds, it is formed when moist air is lifted to a level where ice cystals form but on a larger scale.

    Sometimes the only indication of their presence is given by an observed halo around the sun or moon. Halos result from the refraction of light by the cloud's ice crystals. Cirrostratus clouds, however, tend to thicken as a warm front approaches, signifying an increased production of ice crystals. As a result, the halo gradually disappears and the sun (or moon) becomes less visible.


    Pic courtesy of Bernard Hulshof

  • This cloud consists of long thin filaments known as striations that spread out across the sky. The even texture of this formation results from ice crystals being blown by strong, steady high level winds.


    This image of Fibratus below with a contrail


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  • Nebulosis often creates optical effects. We call them Sundogs
    The uplift that gives rise to this cloud is very gentle and the resulting ice-crystal layer is extremely thin. the only sign of cloud formation will be a slight diminution of the intensity of sunlight.


    Pic by Snowbie

    Pic by Snowbie

  • Cirrocumulus like cirrostratus can form across the entire sky or in patches. What differentiates the two is the presence of instability at the cloud level. This gives the cloud its cumuliform appearance.Again a mass build up of this cloud may indicate an approaching front.



    Pics By Snowbie

  • This cloud can be a blanket of ripples in the sky or sections of the sky with ripples. These ripples are produced by atmospheric waves generated by wind shear. As the with the height of this cloud the wavelength is greatly shortened which makes the ripples much finer.

    Pic by gurramok

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  • Altostratus (mid level layered) Is a featureless cloud which can be a thin white veil of cloud through which the sun is visible or dense grey mantle that blocks out the sun completely. The atmosphere in this region holds significant amounts of moisture and rain or snow can fall from this cloud deck.
    Altostratus is the result of the lifting and condensation of a large airmass by an incoming front.

    Pic by Snowbie

    Pic by Trogdor

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  • Undulatus meaning wave usually forms in a thin layer of altostratus. It appears as a wave motion in the airmass.This motion is normally the result of wind shear when winds move at different speeds and different directions. This then creates vertical eddies of air between layers which rise and dissipates where it falls.

    Pic courtesy of Roger Edmunds

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  • Know for its resemblance to the scales of a fish. The mackerel sky name originated from early mariners.
    This altocumulus formation occurs when a large lifting of a moist air mass usually by an approaching cold front combined with instability at cloud level. It is thought that wind shear(like altocumulus undulatus) gives rise to a more intricate pattern with small waves which produces the much finer mackerel sky pattern.



    Pics by nemonoid

  • This cloud formation is the reult of instability in the midlevel regions. This cloud forms when colder air slides across an area of altocumulus cloud. It is a very good indicator for thunderstorms later in the day. With further surface heating during the day the mid level cas grow into cumulonimbus. The first pic below is from a decaying altocumulus late in the day showing virga trails.
    The second pic is ML instability also late in the day and ahead of Thunderstorms that moved over to Ireland from Wales later in the evening.

    Pic by nilhg

    Pic by Snowbie

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  • Stratus (meaning layer) forms in sheets or layers. It occurs when large areas of moist air rises gently in a stable atmosphere to a level where condensation occurs.
    A common setup in Ireland.
    Also it is the cloud thats asscociated with anticyclonic gloom.

    Pic by Lady North

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  • Orographic clouds are formed when moist air carried on a prevailing wind, is lifted by elevated areas such as a mountain range(upward of 150m) to a level where it condenses. The most common orographic cloud is orographic stratus. This occurs mostly in coastal regions where the air is moisture laden.

    Unlike normal stratus which is moved by wind, this cloud remains stationary. The wind flows through the area of condensation, constantly regenerating the cloud as the air rises and dissipating it as the air descends on the other side of the mountain/hill.


    Pic by Supercell.


    Pic by nemonoid

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  • Cumulus humilis(meaning humble) is the weakest form of convection. Usually witnessed in the morning or early afternoon when convection begins or preceding a warm front as fragmented cumulus. This cloud does not represent any significant weather but if conditions are right, can grow into a Cumulonimbus.
    Also known as fair weather clouds.




    Pics by Danno.

  • Cumulus Mediocris which means moderate is created by slightly stronger convection. This cumulus is tall as it is wide. This cloud is often a transitional stage between the lesser humilis and the more developed congested stage.
    No precipitation occurs from this cloud.


    Pic by Snowbie

  • This is the next stage in the vertical development of a cumulus cloud. Congestus rely not only on convection but instability is required in formation of this cloud. Instability is when the temperature of the surrounding air mass drops with height than normal when cold air sliding over the cloud.
    Unlike the lesser cumulus clouds, this congestus is most common for it's heavy showers but without thunder and lightning.


    Pic by Snowbie

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  • Cumulonimbus Calvus or towering cumulus(TCu) represents a transitional stage between cumulus congestus and cumulonimbus incus(anvil).Calvus occurs when convection and instability combine to push the cloud tops beyond the congested stage up to 30,000 feet. Temperature at this level is well below 0C so instead of water droplets, ice crystals are produced giving the brilliant bright white appearance.No anvil is evident at this stage.

    Pic by Deep Easterly

    Pic by Trogdor

  • Cumulonimbus Incus(anvil) is the mature cumulonimbus or thundercloud. These clouds can reach heights of up to 60,000 feet in tropical and sub-tropical regions(30,000 to 36,000 feet in Ireland.This cloud is refered to as "The King of Clouds".
    This begins as a simple Cumulus humilis in the morning and can quickly go through mediocris,congestus and clavus stages. To continue to grow, convection must combine with instability to produce a powerful updraft. As long as the air is unstable, the Cb grows and expands untill it reaches the top of the troposphere where the temperature levels off and begins to increase with altitude, this change in temperature has the affect of placing a lid on the updraft and the cloud will rise no further.
    The mommentum of the updraft below continues to push up and spread the top out in radial fashion forming the anvil.

    From the pic below you can tell the direction of the storm as the anvil is being pushed by the upper level winds.

    Pic by Deep Easterly

    Next is a small storm over Co.Meath with a small but matured Cb with anvil

    Pic by Snowbie



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  • Mammatus(Latin for breast) forms on the underside of an anvil of a mature Cb cloud. It is formed from a process called reverse direction convection. What happens is moist warm air rises in the Cb, spreads out at the top of the troposphere. The temp levels off and the air stabilises.

    The rising air expands horizontally over cooler cloud free air and creates instability between the two air masses under the anvil, which causes pockets of warm moist air to convect downward. The reverse direction convection is enhanced by the effects of gravity and by precip by the cloud. The process produces near symmetrical protuberances on the underside of the anvil known as mammatus which may cover large areas.

    Mammatus is a sign of a thunderstorm reaching maximum growth and intensity and usually a sign of severe thunderstorms. Mammatus may be several miles away from the centre of the storm.

    Pic by Snowbie


    Pics by DOCARCH


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  • Shelf are assocciated with downdrafts.It is the gust of wind felt of an approaching storm.Cold air is dragged down hitting the warmer layer and which warm is forced up and condenses forming a typical odd looking shape of a shelf.

    It can be safe to say if you see a real prominent shelf cloud,you be in the hail,heavy rain sort of area.


    Pics by Mothman

This discussion has been closed.