Transcript Weather Forecasting

Weather
Forecasting
4.8A Measure and record changes in weather
and make predictions using weather maps,
weather symbols, and a map key.
Why do we predict the weather?
Weather is the condition of
the atmosphere outside at
any given time.
The weather can change quickly
and is sometimes even dangerous!
People need to know how the weather
might change while they are playing or
working outdoors.
Weather Forecasting.
Earth has weather because it is surrounded by
layers of air called the atmosphere. Weather
is what is happening in the atmosphere at a
certain place and time. Most weather occurs
in the lowest layer of the atmosphere.
Weather Forecasting.
Weather is not something we can control.
Meteorologists are scientists who study
weather and try to predict it. They use what
they learn about changing conditions in the
atmosphere to predict the weather for the next
few days or week. These predictions are
called weather forecasts.
Weather Forecasting
Weather happens because the sun warms the
Earth more at the equator than it does at the poles.
This uneven heating causes large masses of air
with different temperatures to form. As these air
masses move, they cause changes in the weather.
Weather Forecasting
Weather has six main factors:
• Temperature
• Air pressure
• Wind speed
• Humidity
• Precipitation
• Cloudiness
Weather Forecasting
The more data meteorologists
can gather, the better they can
forecast the weather.
Meteorologists use a
variety of tools to collect
different weather data.
Weathering Forecasting
The most common weather tools are:
A thermometer is a
weather tool used
to measure the
temperature.
By observing wind vanes,
we can know the direction
of the wind.
An anemometer is a
weather tool that
measures wind
speed.
Weathering Forecasting
The most common weather tools are:
Barometers measure
air pressure.
Knowing the air
pressure can help
predict fair or rainy
weather.
A rain gauge is used to
collect precipitation. Using
measurements on the
side, you can see how
much precipitation fell.
Clouds are made of
water, either small liquid
water drops or tiny
pieces of ice.
Meteorologists rank
clouds according to their
height and whether they
are puffy or flat.
Clouds reflect weather patterns
and play a role in what the
weather does. They are sources
of precipitation as well as affect
the temperatures of our
atmosphere. Clouds block
incoming sunlight during the day,
which cools the air, but they can
also block outgoing radiation
from the Earth, which can warm
temperatures.