Download Thunderstorms

What are thunderstorms???
• A thunderstorm is a storm with lightning and
thunder. Its produced by a cumulonimbus cloud,
usually producing strong winds, heavy rain and
sometimes hail.
WEATHER PHENOMENON
CONTACT WITH THUNDERSTORMS
Temperature
warm
Wind
strong
Precipitation
Heavy rain or sometimes snow, sleet, hail,
no precipitation.
Clouds
cumulonimbus
Front
cold front
Why do thunderstorms form??
• Thunderstorms are powered by the energy from the sun.
All weather on Earth is caused by the sun’s uneven heating
of the planet’s atmosphere. As the sun heats some parts of
the atmosphere, the warm, lighter air in those regions
rises, creating a zone of low atmosphere pressure. Cool air
rushes in, replacing the air that has risen and producing
winds. Such winds then carry all kinds of weather, from
sunshine to rain, hail and snow.
• Thunderclouds need moisture and warm, rising air to
develop. In sunny weather, the sun’s radiation warms the
ground which in turn and heats air near the surface of
Earth. The sun also evaporates water from the surface of
seas, lakes and from wet ground. The warm air rises, taking
the water vapor with it. As the air rises, it cools and the
water vapor condenses to from clouds.
• It can also develop in weather system called fronts,
where winds blow warm and cold air masses
together, and in mountainous regions, where warm,
moist air is forced upward by mountain slopes.
When and where do thunderstorms develop?
•
Thunderstorms can strike anywhere on Earth, but
they usually develop in locations with warm, humid
weather. As a result, they occur most commonly in the
tropics, regions around equator. In many areas of
Central Africa, Southeast Asia, and northern South
America, thunderstorms happen more than 100 days
each year.
•
Thunderstorms also occur commonly in temperate
parts of the world, especially during the summer. In
these areas, storms often break in the afternoon or
evening, after the heat built up. Thunderstorms occur
much less frequently in such cold and dry areas as the
polar regions or deserts.
The places on Earth with the most thunder
•
Tororo, in Uganda, East Africa, holds the record for
the greatest number of thunderstorms per year.
Tororo experienced thunder an average of 251 days a
year during the 10-days period between 1967 and
1976. The town of Bogor, on the island of Java,
Indonesia, is another location that commonly
experiences thunderstorms. In the United States,
thunderstorms occur most commonly in the
Southeast, particularly in Florida.
SAFETY IN THUNDERSTORMS
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People
can stay
safe in aprotect
thunderstorm
by following
a few
Lightning
conductor
buildings
by
channeling
simple rules:
electric
current
safelyordown
to the ground. A metal
Seek shelter
in a house
large building
rod
fixed
tallest part
building
is connected
Don’t
usetoa the
telephone
with of
a acord,
expect
during an
emergency,
becausewire
electric
currentthat
fromruns
lightning
to
a long cooper
or cable
into can
the
travel down wires.
ground. If lightning strikes, electric current passes
If you caught outdoor, never take shelter under a lone tree.
harmlessly
down
cable.
In bicycles
additional,
tall
Stay away from
metalthe
objects
such as
and don’t
buildings
protect shorter, neighboring buildings by
use an umbrella.
If you are swimming,
attracting
lightning.leave the water as quickly as possible
In the flat terrain like a beach, crouch to avoid being the
tallest point in the landscape.
It is safe to sit in a car, be sure to close the windows and
don’t touch any metal parts.