Unit 92: Weather 3

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Unit 9-2 Weather 3

• Weather Instruments and Observations.
• Station Model Symbols.
• Isotherms and Isobars.
• Front and Air Mass Symbols.
• Weather Maps.
• Forecasting the Weather.

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TAKS Practice Weather 3

• What kind of front is shown in the diagram to the
  right?(a) cold (b) warm (c) stationary
• What kind of front is shown in the diagram to the
  right?(a) cold (b) warm (c) stationary
• What kind of front is shown in the diagram to the
  right?(a) cold (b) warm (c) stationary

3
TAKS Practice Weather 3

• What kind of front is shown in the diagram to the
  right?(a) cold (b) warm (c) stationary
• What kind of front is shown in the diagram to the
  right?(a) cold (b) warm (c) stationary
• What kind of front is shown in the diagram to the
  right?(a) cold (b) warm (c) stationary

4
TAKS Practice Weather 3

• What kind of front is shown in the diagram to the
  right?(a) cold (b) warm (c) stationary
• What kind of front is shown in the diagram to the
  right?(a) cold (b) warm (c) stationary
• What kind of front is shown in the diagram to the
  right?(a) cold (b) warm (c) stationary

5
TAKS Practice Weather 3

• What kind of front is shown in the diagram to the
  right?(a) cold (b) warm (c) stationary
• What kind of front is shown in the diagram to the
  right?(a) cold (b) warm (c) stationary
• What kind of front is shown in the diagram to the
  right?(a) cold (b) warm (c) stationary

6
Guiding Questions Weather 3

• What instruments do meteorologists use to measure
  temperature, humidity, air pressure, wind and
  precipitation? (pp.462, 469)
• What is a station model, and what information is
  recorded in it? (p.477)
• What are isotherms and isobars, and how are they
  used by meteorologists? (p.477)
• What symbols do meteorologists use to indicate
  pressure areas, fronts and precipitation on
  weather maps? (p.478)
• How do meteorologists use weather maps to
  forecast weather? (complete activity on p.479)

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1. What instruments do meteorologists use to
measure temperature, relative humidity, air
pressure, wind and precipitation?

• A thermometer is used to measure temperature.
• A hydrometer is used to measure relative
  humidity.
• A barometer is used to measure air pressure or
  barometric pressure.
• A wind vane is used to measure wind direction and
  a wind anemometer is used to measure wind speed.
• A rain gauge is used to measure precipitation.

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2. What is a station model, and what information
is recorded in it?

• The station model is a system of recording
  weather on a weather map using as little space as
  possible. The full key to weather map symbols is
  in the textbook on p.820.

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3. What are isotherms and isobars, and how are
they used by meteorologists?

• Isotherms are lines on a weather map indicating
  all places that have the same temperature. They
  are used to show where warm and cold air masses
  are generally located.
• Isobars are lines on a weather map indicating all
  of the places on the map having the same air
  pressure. They are used to show where high
  pressure systems and low pressure systems are
  located. They also give an indication of wind
  speed and direction. The closer the isobars are
  to one another, the faster the wind speed.

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4. What symbols do meteorologists use to indicate
pressure areas, fronts and precipitation on
weather maps?
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5. How do meteorologists use weather maps to
forecast weather?

• By plotting all of the air masses, fronts and
  temperatures on a series of weather maps over
  time, meteorologists find the pattern and speed
  of movement of weather systems, and make
  predictions on how those systems will move.
• For example, if a cold front moving at 20km per
  hour passes through Wichita Falls (200km from
  Dallas) at 10pm, and the temperature drops to
  below 0C and snow begins to fall there, the
  meteorologist may predict the front will arrive
  in Dallas by 8am, and snow will then fall in
  Dallas.

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5. Forecasting (cont.)

• Today, many more observations are made from
  satellites, and all weather observations are
  entered into a super-computer. An atmospheric
  model (a computer program) in the computer makes
  the weather predictions. The program is
  constantly improved as meteorologists learn from
  past prediction mistakes.

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5. Forecasting (cont.)

• Complete the activity Reading a Weather Map on
  p.479 of your science textbook, using the weather
  map on p.478, and the key to weather symbols on
  p.820 to answer the questions, and this
  additional question
• What is the weather is Dallas going to be in the
  next 24 hours after the time shown on the weather
  map?