Activity 69, “Forecasting Weather”!

from! Issues & Earth Science: Student Book! !

! ! ! ©2012 The Regents of the University of California! 69 Forecasting Weather

N ou have learned that meteorologists collect data about the O I earth’s weather. They often use that data to construct weather I T N G A Y V E S T I maps. Meteorologists then use those maps to predict what the weather will be like in the next few hours, the next day, or for the next several days. This is known as a weather forecast.

When forecasting weather, meteorologists sometimes refer to cold fronts, which form when cold air moves in and replaces warm air. The cold air pushes the warm air up, forming high columns of clouds, as shown below. Cold fronts usually cause cooler temperatures. A warm front occurs when warm air moves in and replaces cooler air. Warm fronts bring in warmer temperatures. They also create cloudy condi- tions that usually last longer than the cloudy conditions produced by cold fronts.

Cold Front

Warm air mass

Cold air mass

Warm Front

Warm air mass Cold air mass

E-87 Activity 69 • Forecasting Weather

CHALLENGE

What information is found on a weather map? How can a weather map be used to forecast weather?

MATERIALS

For each student 1 Student Sheet 69.1, “Summarizing Weather Reports” 1 Student Sheet 69.2, “Map of Iowa”

PROCEDURE

1. Work with your group to review the information in the table below, “Weather Map Symbols.” Make sure that you are familiar with the different weather symbols and what they mean.

Weather Map Symbols

Weather Symbol Associated Weather

Precipitation Rain, snow, fog, or other forms of precipitation

Cold front Cooler temperatures, possible precipitation

Warm front Warmer temperatures, possible precipitation

Low pressure L Cloudy skies, possible precipitation High pressure H Clear skies Hurricane Damaging winds, rain, possible flooding

Tornado watch Area where tornadoes may occur, possible severe thunderstorms

Tropical storm Very strong winds and heavy rains

E-88 Forecasting Weather • Activity 69

2. Your teacher will assign your group one of the weather maps for August 24–31 shown on pages 92–93.

3. Work with your partner to summarize the weather on this map. Identify: • weather fronts • precipitation • areas of high and low pressure •anyunusualweatherevents,suchasatornadowatchora hurricane

Be sure to discuss with your partner each type of weather and where in the country it is occurring. For example, if you were to begin to summarize the weather for August 24, you might say, “There is a cold front stretching from Arizona northeast up to Min- nesota.”

4. Work with your partner to write a weather report for your assigned day. You can do this by describing the weather that is associated with each weather symbol (see the table). As you summarize cur- rent weather conditions, make sure to describe: • weather fronts and possible changes in temperature • areas of precipitation • clear or cloudy skies due to changing pressure •anyunusualweatherevents,suchasatornadowatchora hurricane

In your science notebook, write your weather report in complete sentences and in the present tense, as if you were reporting the weather on television or the radio. For example, if you were to begin to summarize the weather on August 24, you could write, “The cold front stretching from the southwest up to Minnesota is causing cooler temperatures and may result in some precipitation.”

5. Share your weather report with the other half of your group. Dis- cuss similarities and differences in your weather reports, and make any needed changes.

6. Prepare one weather report to present to the class.

E-89 Activity 69 • Forecasting Weather

7. Read the statements on Student Sheet 69.1, “Summarizing Weather Reports.” You will respond to these statements after lis- tening to your classmates report on the weather for each of the eight days from August 24 to 31.

8. Have your group present its weather report and listen to other groups reports.

9. After listening to all eight weather reports, complete Student Sheet 69.1.

10. Based on the weather reports you heard, forecast the weather for Cleveland, Ohio for September 1. Describe likely fronts, tempera- ture changes, pressure changes, precipitation, and severe weather that may arrive.

Hint: Look at the pattern of weather over the eight days. Use your knowledge of how weather moves across the United States to pre- dict what type of weather is likely to occur in Cleveland.

Locator Map for Cleveland, Ohio

WA L. Superior L. Michigan NH L. Ontario ME MONT VT Pacific N DAK L. Huron Ocean ORE MINN IDAHO S DAK WISC L. Erie NY WYO MICH MA RI IOWA PENN CONN NEV NEBR Cleveland NJ UTAH ILL IND OHIO CALIF W DEL COLO VA MD KANS VA MO KY NC Atlantic TENN Ocean ARIZ OKLA N MEX ARK SC N MISS ALA GA EW TEX S LA

FLA

Gulf of Mexico

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G Forecasting Weather • Activity 69

ANALYSIS

1. a. Based on the patterns you observed in the weather maps, in what direction does weather generally travel across the United States? b. Think back to your work in the last activity. In what direction does the prevailing wind move across the United States? c. How does the movement of the atmosphere globally affect weather locally?

2. Below is weather data collected for Iowa on September 15. Your teacher will give you Student Sheet 69.2, “Map of Iowa.” Use the information provided and your knowledge of weather maps to place the appropriate weather symbols on Student Sheet 69.2. Be sure to construct a key for your map. •WarmfrontextendingfromLincoln,Nebraskanortheastto Mason City, Iowa • Rain all along the warm front • Low-pressure system in and around Des Moines, Iowa

3. Reflection: People often complain about the unreliability of weather forecasts. Why do you think meteorologists are sometimes wrong about what the weather will be like?

E-91 Activity 69 • Forecasting Weather

Weather Maps: August 24 WA through August 31 NH ME MONT VT ORE N DAK MINN IDAHO S DAK WISC NY WYO MICH MA RI IOWA PENN NEV CONN NEBR OHIO UTAH COLO ILL IND NJ CALIF DEL KANS H VA MD MO KY NC TENN OKLA ARK ARIZ N MEX SC MISS ALA GA HTEX LA August 24 FLA

WA NH ME MONT VT ORE N DAK MINN IDAHO S DAK WISC NY WYO MICH MA PENN RI IOWA CONN NEV NEBR OHIO UTAH ILL IND NJ CALIF COLO W DEL KANS VA VAH MD MO KY NC TENN OKLA ARK LARIZ N MEX SC MISS ALA GA TEX LA H August 25 FLA

WA NH ME MONT VT ORE N DAK MINN IDAHO S DAK WISC NY WYO MICH MA PENN RI IOWA CONN NEV NEBR OHIO UTAH ILL IND NJ CALIF COLO W DEL KANS VA VA MD MO KY NC TENN H OKLA ARK ARIZ N MEX SC L MISS ALA GA TEX LA August 26 FLA

WA NH ME MONT VT ORE N DAK MINN IDAHO S DAK WISC NY WYO MICH MA PENN RI IOWA CONN NEV NEBR OHIO UTAH ILL IND NJ CALIF COLO W DEL KANS VA VA MD MO KY NC TENN H OKLA ARK ARIZ N MEX SC L MISS ALA GA TEX LA August 27 FLA

E-92 Forecasting Weather • Activity 69

WA NH ME MONT VT ORE L N DAK MINN IDAHO S DAK WISC NY WYO MICH MA PENN RI IOWA CONN NEV NEBR OHIO UTAH ILL IND NJ CALIF COLO W DEL KANS VA VA MD MO KY NC TENN LOKLA ARK ARIZ N MEX SC MISS ALA GA TEX LA August 28 FLA

WA NH ME MONT VT ORE N DAK MINN IDAHO S DAK WISC NY LWYO MICH MA PENN RI IOWA CONN NEV NEBR OHIO UTAH ILL IND NJ CALIF COLO W DEL KANS VA VA MD MO KY NC TENN OKLA ARK ARIZ N MEX SC MISS ALA GA TEX LA August 29 FLA

WA NH ME MONT VT ORE N DAK MINN IDAHO S DAK WISC NY WYO MICH MA L PENN RI IOWA CONN NEV NEBR OHIO UTAH ILL IND NJ CALIF COLO W DEL KANS VA VA MD MO KY H NC TENN H OKLA ARK ARIZ N MEX SC MISS ALA GA TEX LA August 30 FLA

WA NH ME MONT VT ORE N DAK MINN IDAHO S DAK WISC NY WYO L MICH MA PENN RI IOWA CONN NEV NEBR OHIO H UTAH ILL IND NJ CALIF COLO W DEL KANS VA VA MD H MO KY NC TENN OKLA ARK ARIZ N MEX SC MISS ALA GA TEX LA August 31 FLA

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