Predicting the Weather

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Transcript Predicting the Weather

Weather Forecasting
• A weather forecast is a prediction of the weather.
• You use weather forecasts to decide what to wear
each day and what activities you can participate in.
• Scientists use tools to measure the current weather
to help make their predictions about future
Weather Maps
• Weather maps can show what the weather was like
in a place on a certain day.
• Scientists use data from weather stations all over
the world to create weather maps.
Weather Maps and Symbols
Click the link below to see an
explanation of weather maps:
Air Masses
• Weather maps show the movement of air masses. An air
mass is a large body of air with about the same
temperature and humidity throughout.
• There are 4 basic types:
– Cold and Dry
- Warm and Dry
– Cold and Humid
- Warm and Humid
• Weather Maps also show fronts. A front is a
place where 2 different air masses meet.
Click below to learn
more about air
masses and fronts:
Cold Front
• Cold air mass
bumps against
warm air mass
• Strong storms
happen here
(thunderstorms in
warm weather,
snowstorms in
• Causes
temperature in an
area to drop.
Warm Front
Stationary Front Occluded Front
• Warm air mass
• Forms when 2 air
• An occluded front
meets colder air
masses meet and
is a combination of
mass and rises over
stop moving
two fronts that
• Bring clouds and
form when a cold
• Stratus clouds form
front catches up
which often bring
lasting longer
and overtakes a
because air masses
warm front.
• Causes
are not moving
temperature in an
area to rise
Air Pressure
• Air pressure is measured with a barometer.
• Low air pressure usually brings rainy or stormy
• High air pressure usually brings fair weather.
Weather Patterns in the United States
• In the United States, weather usually moves from WEST to EAST.
• Rain forming over the Pacific Ocean moves east over California and
weather forming over the middle of the U.S. often moves towards
North Carolina and other eastern states within days.