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Wednesday, April 27, 2011

How do Clouds Form

While there are a wide variety of cloud shapes and sizes, they are all made of the same thing: condensed water or ice. Clouds form when rising air, through expansion, cools to the point where some of the water vapor molecules "clump together" faster than they are torn apart by their thermal energy. Some of that water vapor condenses to form  cloud droplets or ice crystals which can be observed by us.
formation of a convective cloud

 To be more specific,  in order for these water droplets or ice crystals to form into clouds in the atmosphere, a series of processes have to happen, and different types of clouds form from different processes. The four main ways that clouds can form are:
-Surface Heating
-Mountains and Terrain
-Weather Fronts (cold or warm)
-Air Masses Being Forced to Rise
All of these processes involve the cooling of air. Warm air is able to hold larger amounts of water vapor than cool air, so when air cools it is no longer able to hold all of the water vapor it was able to hold when it was warm. This extra water vapor begins to condense out of the air into liquid water droplets.

there are five main types of clous, which are , cirrostratus clouds, cirrocumulus clouds,altocumulus clouds and cumulus clouds.
cirrus cloudsthere are also four types of cirrus clouds. two kinds of cirrus clouds that we should know is  cirrus Fibratus dsand Spissatus. they are all ice clouds, if you see these to kinds of clouds, it means it is a good wather now. however, the weather also depend on the winds. if the winds are from the E to S, precipitation is likely to occur with 20 to 30 hours of that time period too.


there are 3 types of cirrostratus clouds. these clouds cover up the whole sky. these clouds contain ice. if you see these clouds in the sky, it means that precipitation is likely to occur in 15 to 25 hours.
cirrostratus clouds
cirrocumulus clouds
cirrocumulus clouds are all ince clouds. if you see these clouds in the morning, then that means you will likely to see come thunderstrom showers in the afternoon.
Altocumulus Clouds
Altocumulus clouds are mostly water and ice clouds. one type of altocumulus clouds, undulatus clouds, is the sign for heavy rain.
Cumulus Clouds
Cumulus clouds are the most common clouds. There are 4 types of Cumulus clouds; Humilis, Vertical Growth, one kind of cumulus clouds that we should know is Vertical Growth can also occur during fair weather conditions and can spawn afternoon showers. 
Vertical Growth
Hope everyone can learn from what i post, clouds formation is amazing right ?!!? :D
Zhou Weixin(25)  JH 405


  1. Well,since nobody comment on my post yet, then i comment on my own post first :D Thanks weixin for his excellent post! i want to add one more point that any planet having an atmosphere in the solar system will have clouds. Clouds exist on the other planets like Venus, Mars, Jupiter and Saturn. In other words clouds are condensed droplets suspended in the atmosphere above the surface of the Planet. One interesting concept in the formation of clouds is the ice memory. It has been found that for clouds to form on clay for the first time, the required temperature is a minus ten degrees celcius. However, later, the clouds will form around the same clay at just minus five degrees celcius.

  2. Hellooo.
    I always thought that clouds were just water droplets. Even though snow must have come from somewhere, somehow it never occurred that there were ice particles in the clouds. But now I know!

    Anyway, does this mean that a mixture of snow and rain, or sleet, means that there are water droplets as well as ice particles? Ice should melt at temperate about 0 degree Celsius right? At water droplets at below 0 degree Celsius should freeze right?
    So how come there are "in-betweens" that result in sleets?

    Oh and also, fun fact!
    The term ice cloud has been used to describe clouds of carbon dioxide on Mars. Such clouds can be sufficiently large and dense to cast shadows on the Martian surface. Clouds of water ice also occur on Mars.

    Cherie Chang (05)

  3. Thanks Weixin for that informative post :) After seeing all that clouds, im even more intrigued by the patterns clouds can form. They are so pretty!

    Anwz, what i wanted to add on to Weixin's post is that clouds are also classified according to cloud bases:

    (1) High clouds with bases above 20 000 ft
    (2) Medium clouds with bases between 7 000 ft to 20 000 ft and
    (3) Low clouds with bases less than 7 000 ft

    High clouds consists mainly of ice particles. There are are 3 different types of high clouds:

    (a) Cirrus clouds. 
    (b) Cirrocumulus clouds. 
    (c) Cirrostratus clouds.  

    Medium clouds consists of water or water and ice particles. There are 3 different types of medium clouds:

    (a) Altocumulus clouds. 
    (b) Altostratus clouds. 
    (c) Nimbostratus clouds.

    Low clouds are convective  clouds with cloud tops extending beyond 40 000 ft. There are 4 different types of low clouds:

    (a) Stratocumulus clouds. 
    (b) Stratus clouds. 
    (c) Cumulus clouds. 
    (d) Cumulonimbus clouds.

    Yangting(10) :D

  4. Cooool. I always thought clouds were just clouds, and I only paid attention to the shapes of the clouds, trying to imagine different animals and stuffs out of the clouds. Now I know that there are different types of these clouds out in the world :D

    What kind of clouds are predominant in Singapore, though??

    Clarissa (7)

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