Name:
Lesson 3 of Unit 4 How Is Weather Predicted?
Use page 297 to define these terms:
meteorology ________________________________________________
barometer __________________________________________________
anemometer ________________________________________________
hygrometer _________________________________________________
air mass ____________________________________________________
___________________________________________________________
front ______________________________________________________
Measuring Weather
The study of weather is called ________________________. Scientists use
certain instruments to make predictions about the weather called __________________.
A _____________________ is used to measure air pressure. Air pressure and air
temperature are interrelated. Colder air has higher readings of pressure due to its density
and has less __________ in it than warmer air. This can help people determine the
likelihood of rain in the future by knowing what the air pressure is at a certain time and
place. The lower the air pressure reading, the _____________ the chance of rain.
Knowing wind speed and direction is important because wind often signals
changes in ____________________. Just observing the sky can be a way of predicting
weather changes. Some cloud types are associated with different types of weather. High
_____________ clouds and small ______________ clouds mean good weather is ahead.
Air Masses:
Air moves around the Earth systematically in large “bodies”, called _________
_______________, that have similar temperatures and humidity. They can be warm or
cold. An air mass takes on the characteristics of the ______________ it formed over.
Look at the picture on this page and read the third paragraph. Air masses formed over
land (continental) can be hot or cold, but both have __________ humidity. Air masses
formed over the oceans have ___________ humidity. Air masses over our country
generally move from __________ to ___________.
Fronts:
A ___________ is the border where two different air masses meet. Most weather
changes occur along these _____________. A cold front forms where a cold, _________
air mass moves under a warm, less dense air mass causing the warm air to rapidly rise.
We know that as warm air rises, it _____________. When it is suddenly cooled the water
vapor ____________ into a form of precipitation, and can cause heavy rains or snows for
a short amount of time. A warm front is where warmer, ________ dense air slowly slides
up over a cold ______ ___________. These can produce ____________ clouds, which
can bring precipitation for longer periods of time than the cold fronts.
After looking at the diagram on page 303, draw a picture of these two fronts and use
these terms to label your pictures. Use arrows to show directionality and add color.
warm air mass, cold air mass, rapidly rising air, slowly rising air, severe weather, long-lasting rains
Weather Maps:
Weather maps use _______________ to show the weather. After reading page
304 and looking at the weather map, use the map below to develop your own weather
map using the details provided. Use colored pencils or crayons to make your map pop.
Remember, most of our weather moves from west to east across our country. Make a
map key to show what your symbols stand for and label where needed. Have fun and BE
NEAT.
1.
Weather = 1.Cold front moving east is over the western states through Montana, Utah, and
California (like map on page 304).
2.
Rains are all along the front edge of this air mass.
3.
Warm front moving northeast is over Texas, Oklahoma, and Colorado.
4.
Thunderstorms in front of this mass.
5.
Cold front moving southeast from Canada over the Great lakes causing snow in Michigan,
Minnesota, and Wisconsin.
6.
Low pressure areas over Idaho and Wisconsin. High pressure over Arizona and Florida.
7.
High and low temperatures: San Francisco 67/45, LA 86/65, New York City 75/46.
8.
Dry weather over Nebraska and Maine.
9.
Sunny weather over Florida and Texas.
10. Add one of your choice. Write it in here, and then put it on your map. ___________________
_________________________________________________________________________
Forecasting Weather:
Weather forecasts depend on many variables. One main variable is __________
_________________. Another variable is air pressure. If you see a low-pressure system
you can assume ___________ weather is on the way, whereas, a high-pressure system
signifies _____________ weather. The _____________ ____________________ is the
idea that very small changes can have great effects on a weather system. Watch out!!!
Optional:
If time allows read the math connection question on page 307. Figure out the mean (average) and then see
how accurate you are for the actual rainfall in the Los Angeles area for the year 2005. Use the space below
to show your work.