Transcript Handout 24

Chapter 24 Section 4
Handout
Forecasting the Weather
1
 How did people of early civilizations meet
the challenges of weather prediction?
 Many attributed weather conditions to gods,
and some tried to forecast the weather using
the positions of the moon and stars.
2
 Describe the origins of scientific weather
forecasting.
 It began with the invention of basic weather
instruments such as the thermometer and the
barometer.
 The invention of the telegraph in 1844 allowed
meteorologist to share information quickly.
3
 List seven types of weather observations
reported from weather stations around the world.
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Barometric pressure
Surface wind
Precipitation
Temperature
Humidity
Cloud cover
General weather conditions
4
 The data that weather stations collect are
transferred:
 Onto weather maps
5
 What do meteorologists use to
communicate data on a weather map that
can be understood around the world?
 Symbols and colors
6
 A pattern of meteorological symbols that
represents the weather at a particular
observing station and that is recorded on a
weather map is:
 A station model
Science Word Review
 Lines that connect points of equal
temperature on a weather map are called:
 Isotherms
Science Word Review
 Lines on a weather map that connect
points of equal atmospheric pressure are:
 Isobars
7
 What do common weather symbols
describe?
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Cloud cover
Wind speed
Wind direction
Weather conditions
 Type of precipitation
 Storm activity
8
 Besides cloud cover, wind speed and
direction, and weather conditions, what
else do stations models indicate?
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Temperature
Dew point
Atmospheric pressure
Barometric tendency
9
 What is the dew point and what does it
indicate about the air?
 It is the temperature to which the air must cool
in order for more water vapor to condense
than to evaporate in a given amount of time.
 It indicates how high the humidity is, or the
amount of water vapor there is in the air.
10
 On a weather map, what identifies a front?
 Sharp changes in wind speed and direction,
temperature, or humidity.
11
 How are areas of precipitation commonly
marked on weather maps?
 With different symbols or colors for different
kinds and amounts.
12
 How do meteorologists forecast the
weather?
 They regularly plot the intensity and path of
weather systems on maps.
 They make comparisons with recent maps to
follow the progress of weather systems.
 Then they make predictions based on their
observation.
13
 What types of weather information can be
predicted most accurately?
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Temperature
Wind direction
Wind speed
Cloudiness
Precipitation
14
 What types of weather information are
more difficult to predict accurately?
 It is often difficult to predict exactly when
precipitation will occur or the exact amount.
15
 nowcasts
 use radar and enable forecasters to focus on
timing precipitation and tracking severe
weather
16
 daily forecasts
 predict weather for a 48-hour period
17
 extended forecasts
 predict weather accurately 3 to 7 days ahead
18
 medium-range forecasts
 predict weather 8 to 14 days ahead using
computer analysis of slowly changing largescale movements of air
19
 long-range forecasts
 predict weather over monthly and seasonal
periods
20
 watch
 issued when the conditions are ideal for
severe weather
21
 warning
 issued when severe weather has been
spotted or is expected within 24 hours
22
 What is cloud seeding?
 Particles are added to clouds to cause the
clouds to precipitate
23
 How has cloud seeding been used in
Russia?
 In Russia, cloud seeding has been used with
some success on potential hail clouds to
produce rain rather than hail.
24
 How have scientists attempted to control
hurricanes?
 Hurricanes have been seeded with freezing
nuclei in an attempt to reduce the intensity of
the storm
25
 Why have scientists abandoned storm and
hurricane control?
 Because it is not an attainable goal with
current technology
26
 How have scientists attempted to control
lightning?
 by seeding potential lightning storms with
silver-iodide nuclei
27
 What have been the results of attempts at
lightning control?
 Seeding potential lightning storms has
seemed to modify the occurrence of lightning,
but results have been inconclusive.
The End