WEATHER MAP ANALYSIS
INTRODUCTION
Weather maps give the current weather conditions for an entire region. This enables the meteorologist to see
how weather conditions are interacting with each other over a large area. This interaction can then be used to
help forecast weather for any location on the map. Weather maps can be found in local newspapers,
magazines, and of course seen on television during news broadcasts or the weather channel.
MATERIALS : Weather Map, Station Model Reference Page, Colored Pencils, Textbook Page 457
OBJECTIVES: During this lab activity you will:
1. Use past experiences with plotting and interpreting weather station models and their symbols in order to
analyze the weather conditions at a particular locality on the map of North America.
2. Be able to draw warm and cold fronts on a weather map and determine the type of weather associated with
the passage of the front.
PROCEDURES
1. The Weather Observations Chart, on the next page, gives information of weather variables as measured at
different stations in the United States and Canada. This information must be plotted on the map, using the
correct placement of numbers and symbols as shown on the Reference Tables.

Wind directions are given from which the wind is blowing. Place a line indicating the correct direction of
the wind around the station model circle for each city given. Draw each of the wind arrow lines in black
pencil.

Wind speed must be represented by placing “feathers” on the shaft of the wind arrow. Refer to the
station model reference page or your notes for the correct symbol to use and draw the “feathers” for
your wind speed in black pencil.

Air pressures are recorded in millibars. Remember to convert the pressures to short form. If the
pressure begins with “10”, drop the “10”. Write all air pressures on the station model in red pencil.

Temperatures are given in degrees Fahrenheit. Write the temperature in its correct position around the
station model circle in blue pencil.

Present weather is given for some cities. Draw in the appropriate present weather symbol in green
pencil.

The amount of cloud cover at each station is to be drawn in black pencil.
2. Your teacher will show you how to draw isobars that will connect station models of equal pressures.
Starting with an air pressure of 1024.0 you will draw isobars at 4 millibar intervals. Continue with isobars for
pressures of 1020.0, 1016.0, 1012.0, 1008.0, and 1004.0, in black pencil.
3. Find the observation station that has the lowest atmospheric pressure and put a large “L” just above it. This
represents the center of the low pressure system.
4. Find the observation station that has the highest atmospheric pressure and put a large “H” just above it.
This represents the center of the high pressure system.
5. Based on change in temperature and wind direction, locate and draw the warm front and cold front on the
map using the appropriate symbol and color.

The cold front extends towards the southwest from the low pressure center (L). The front will be
located between stations where winds change from a northwest to southwest direction. Temperatures
will be colder behind the front and warmer ahead of the front.

The warm front extends towards the east of the low pressure center (L). This front will be located
between stations where winds change from northeast to southeast. Temperatures will be warmer
behind the front and colder ahead of the front.
Weather Observations Chart
WEATHER
OBSEVATIONS
Weather Station
Wind
Speed
(kts)
Wind
Direction
Air
Pressure
(mb)
Temp.
(°F)
Seattle
Bend
San Francisco
Los Angeles
Phoenix
Ely
Dubois
Helena
Medicine Hat
Bismarck
Casper
Pueblo
Roswell
Del Rio
Galveston
Dallas
Oklahoma City
Burwell
Kansas City
Minneapolis
Sioux Lookout
Chicago
Little Rock
New Orleans
Nashville
Cincinnati
Detroit
Sault Ste. Marie
Ert
Quebec
Boston
Buffalo
New York
Hatteras
Charleston
Atlanta
Jacksonville
Tampa
Miami
5
10
10
15
10
10
20
15
20
20
10
10
20
20
5
30
45
20
10
15
20
10
10
5
5
5
10
15
5
10
10
5
10
15
15
5
5
5
10
SE
NE
NE
N
NW
N
NW
SW
SSW
W
NW
NW
NW
NW
SW
NW
NW
NNW
NW
NW
SW
NW
NW
SW
S
NE
NE
NE
E
NE
NE
ENE
ENE
N
SE
SE
SSE
S
SE
1024.0
1024.0
1020.0
1019.0
1018.0
1020.0
1024.0
1020.0
1020.0
1016.0
1017.0
1016.0
1016.0
1012.0
1011.0
1011.0
1011.0
1012.0
1008.0
1012.0
1016.0
1007.0
1008.0
1008.0
1000.0
1004.0
1007.0
1011.0
1012.0
1010.0
1010.0
1008.0
1010.0
1008.0
1006.0
1004.0
1007.0
1008.0
1010.0
42
40
48
41
45
37
38
41
40
48
50
47
48
55
75
60
57
52
58
51
46
58
60
73
68
57
54
50
48
50
52
52
56
65
70
80
78
82
85
Present
Weather
Fog
Fog
T-Storm
T-Storms
Rain
Fog
Fog
Rain
Rain
Cloud Cover
(%)
0
0
25
0
0
0
0
0
0
0
0
0
0
25
100
0
0
25
0
0
25
0
50
100
100
50
25
75
50
25
100
50
100
100
100
25
0
25
0
PRESSURE & TRENDS
Sea-level pressure is plotted in tenths of millibars (mb), with the leading 10 or 9 omitted. Below are some sample
conversions between plotted and complete sea-level pressure values:
410 = 1041.0 mb
103 = 1010.3 mb
987 = 998.7 mb
872 = 987.2 mb
The pressure trend has two components, a number and symbol, to indicate how the sea-level pressure has changed
during the past three hours. The number provides the 3-hour change in tenths of millibars, while the symbol provides a
graphic illustration of how this change occurred. Below are the meanings of the pressure trend symbols:
Weather Map Analysis
Name _________________________________________ Date _________________________ Block ________
CONCLUSIONS – Using your weather map, answer the following questions.
Circle the correct answer for the choices appearing in [ brackets ].
1. What kind of air pressure system is affecting the Northwest coast of the U.S.? [ High / Low ]
2. What kind of air pressure system is affecting the Southern Gulf States area of the U.S? [ High / Low ]
3. According to your map, which type of pressure system is the precipitation located near? [ High / Low ]
4. What type of precipitation is associated with the cold front? _____________________________________
5. What type of precipitation is associated with the warm front? ___________________________________
6. When the isobars on a weather map are spaced far apart, this shows that the wind speeds in that area
are moving [ fast / slow ].
According to your map and/or your previous knowledge:
7. How do the winds around a Low Pressure center circulate? [ Clockwise / Counterclockwise ]
8. How do the winds around a High Pressure center circulate? [ Clockwise / Counterclockwise ]
9. What type of air pressure is associated with cold temperatures? [ high / low ]
10. What type of air pressure is associated with warm temperatures? [ high / low ]
11. What kind of front will soon pass over Galveston? ___________________
12. In what direction is the front near Galveston moving? ____________________
13. Galveston can expect [ warmer / colder ] temperatures with a(n) [ increase / decrease ] in air pressure.
14. In which direction will the winds come from in Galveston after the front passes?____________________
15. What kind of front will soon pass over Hatteras? ___________________
16. In what direction is the front near Hatteras moving? ____________________
17. Hatteras can expect [ warmer / colder ] temperatures with a(n) [ increase / decrease ] in air pressure.
18. In which direction will the winds come from in Hatteras after the front passes? ____________________
19. Why are there little to no clouds or rain present over the western portion of the United States?
__________________________________________________________________________________
20. Predict the following weather conditions that would be occurring in Washington, DC at the time the other
observations were recorded: (values will be approximated)
______________ - Wind Direction
______________ - Air Pressure
______________ - Temperature
______________ - Present Weather