http://www.weatherwizkids.com/cloud.htm
What are clouds?
A cloud is a large collection of very tiny droplets of water or ice crystals.
The droplets are so small and light that they can float in the air.
How are clouds formed?
All air contains water, but near the ground it is usually in the form of an
invisible gas called water vapor. When warm air rises, it expands and cools.
Cool air can't hold as much water vapor as warm air, so some of the vapor
condenses onto tiny pieces of dust that are floating in the air and forms a
tiny droplet around each dust particle. When billions of these droplets come
together they become a visible cloud.
Why are clouds white?
Clouds are white because they reflect the light of the sun. Light is made up
of colors of the rainbow and when you add them all together you get white.
The sun appears a yellow color because it sends out more yellow light than
any other color. Clouds reflect all the colors the exact same amount so they
look white.
Why do clouds turn gray?
Clouds are made up of tiny water droplets or ice crystals, usually a mixture
of both. The water and ice scatter all light, making clouds appear white. If
the clouds get thick enough or high enough all the light above does not make
it through, hence the gray or dark look. Also, if there are lots of other
clouds around, their shadow can add to the gray or multicolored gray
appearance.
Why do clouds float?
A cloud forms when air heated by the sun. As it rises, it slowly cools it
reaches the saturation point and water condenses, forming a cloud. As long
as the cloud and the air that its made of is warmer than the outside air
around it, it floats!
How do clouds move?
Clouds move with the wind. High cirrus clouds are pushed along by the jet
stream, sometimes traveling at more than 100 miles-per-hour. When clouds
are part of a thunderstorm they usually travel at 30 to 40 mph.
How is fog formed?
There are many different types of fog, but fog is mostly formed when
southerly winds bring warm, moist air into a region, possibly ending a cold
outbreak. As the warm, moist air flows over much colder soil or snow, dense
fog often forms. Warm, moist air is cooled from below as it flows over a
colder surface. If the air is near saturation, moisture will condense out of
the cooled air and form fog. With light winds, the fog near the ground can
become thick and reduce visibilities to zero.
(Graphic Credit: USA TODAY.)
What is lightning?
Lightning is a bright flash of electricity produced by a thunderstorm. All
thunderstorms produce lightning and are very dangerous. If you hear the
sound of thunder, then you are in danger from lightning. Lightning kills and
injures more people each year than hurricanes or tornadoes; between 75 to
100 people.
What causes lightning?
Lightning is an electric current. Within a thundercloud way up in the sky,
many small bits of ice (frozen raindrops) bump into each other as they move
around in the air. All of those collisions create an electric charge. After a
while, the whole cloud fills up with electrical charges. The positive charges
or protons form at the top of the cloud and the negative charges or
electrons form at the bottom of the cloud. Since opposites attract, that
causes a positive charge to build up on the ground beneath the cloud. The
grounds electrical charge concentrates around anything that sticks up, such
as mountains, people, or single trees. The charge coming up from these
points eventually connects with a charge reaching down from the clouds and zap - lightning strikes!
Have you ever rubbed your feet across carpet and then touched a metal
door handle? If so, then you know that you can get shocked! Lightning works
in the same way.
Click Here to see where lightning is currently striking across the U.S.
How hot is lightning?
Lightning is approximately 54,000 degrees Fahrenheit. That is six times
hotter than the surface of the sun!
What color is lightning?
Lightning seems to be clear or a white-yellow color, but it really depends on
the background.
What causes thunder?
Thunder is caused by lightning. When a lightning bolt travels from the cloud
to the ground it actually opens up a little hole in the air, called a channel.
Once then light is gone the air collapses back in and creates a sound wave
that we hear as thunder. The reason we see lightning before we hear
thunder is because light travels faster than sound!
How do you know if lightning is nearby?
If you see dark clouds, then lightning could be present, but the best thing
you can do is to listen for thunder. If you hear thunder, then you need to go
indoors or get in a car. Don't be outside, where lightning could strike! If
your hair stands on end or your skin starts to tingle, lightning maybe about
to strike. Get down on your hands and knees and keep your head tucked in.
Do not lay flat, because it can give lightning a better chance of strike you.
What is ball lightning?
Ball lightning is a rare form of lightning. It usually appears as a reddish,
luminous ball, but can come in any color. Ball lightning is usually spherical in
shape and about one foot in diameter. Hissing noises originate from such
balls and they sometimes make a loud noise when they explode.
Can you tell how far away a storm is?
Yes, you can use thunder to tell how far away a storm is. Next time you see a
storm, count the number of seconds between when you see the lightning and
hear the thunder. Take the number of seconds and divide by 5 and that will
tell you how far away the storm is in miles. For example: If you counted 10
seconds between the lightning and the