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. 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? 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? 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? 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 large-scale 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