LAB: HURRICANE DAVID/HURRICANE GLORIA
Purpose: To plot and compare the paths of Hurricane David (August-September 1979) and Hurricane Gloria
(September 1985).
Background: Most Atlantic Ocean hurricanes get started as a low pressure system in the tropics off the west
coast of Africa. Warm water and moisture laden air supply the energy (latent heat of condensation) for it to
strengthen into an ordinary, average tropical storm. Most tropical storms encounter upper level winds moving in
the opposite direction from the surface winds. As a result, these storms weaken and soon die out. On occasion
the upper level winds support the development of the storm and a hurricane can be created.
Materials: Colored pencils, hurricane tracking map, reference sheet
Procedure: On the hurricane tracking chart, plot the path of each hurricane. Label each point with the date,
time and wind speed as shown using the hurricane symbol.
9/22 date
9 am time
75 wind speed
Join the points with a smooth curve (using a different color pencil for each).
Analysis: Answer questions #1-11 and 13-15 in complete sentences.
1. A tropical storm becomes a hurricane once the wind speeds meet or exceed 74 mph. On what day and time
did each of these storms become hurricanes ?
2. How many days did these storms remain hurricanes ?
3. What part of the United States is most greatly effected by hurricanes ?
4. What causes the greatest damage in a hurricane ?
5. Diagram and describe a storm surge.
6. What effect do land masses have on wind speed of a hurricane? (On the hurricane tracking chart, a hurricane
is approximately the size of a quarter. Therefore, if you place a quarter over the eye of the storm, you will be
able to see the approximate boundaries of the hurricane and when the storm hits land.)
7. What is the most important thing in keeping a hurricane going strong ?
8. How do most people die in a hurricane ?
9. Describe the general compass direction (north, south, east, west) of movement of Hurricane David in the
"tropics" from August 26 to September 3.
10. Describe the general compass direction (north, south, east, west) of movement of Hurricane David in the
"mid-latitudes" or "temperate zone" from September 4 to September 7.
11. Using your knowledge of global wind belts,
a. Which global winds tend to move a hurricane westward in the tropics ?
b. Which global winds tend to move a hurricane northeastward in the mid-latitudes ?
12. Using the hurricane tracking chart's scale, calculate the average distance (in miles) covered by hurricanes in
one day for:
Hurricane David
a. the 9 days from Aug. 26 to Sept. 3
(THE TROPICS)
total miles covered
average miles covered/day
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
b. the 4 days from Sept. 4 to Sept. 7
(THE MID-LATITUDES)
total miles covered
average miles covered/day
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
Hurricane Gloria
a. the 4 days from Sept. 22 to Sept. 25
(THE TROPICS)
total miles covered
average miles covered/day
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
b. the 3 days from Sept. 25 to Sept. 27
(THE MID-LATITUDES)
total miles covered
average miles covered/day
~~~~~~~~~~~~~~~~~~~~~
13. Make a general statement that compares the rate of travel (average distance covered per day) of each
hurricane while in the tropics to their rate of travel while in the mid-latitudes.
14. Thinking about the wind directions around a hurricane, why did eastern Long Island, New York suffer
greater damage than western Long Island during Hurricane Gloria? Your map needs to have been done very
accurately to see this.
15. Would a low pressure system over South Carolina make a hurricane in the Bahamas more or less of a hazard
for the east coast of the USA ? Explain your answer keeping in mind the winds around a low pressure.
REFERENCE SHEET
In August of 1979, Hurricane David became famous as one of the strongest and most destructive hurricanes to
strike the Caribbean region and eastern United States. David was particularly notable for the extensiveness of
its destructive path, which included Haiti, Dominican Republic and later, the east coast of the United States.
Property damage was estimated at more than $1,000,000,000 and even with the timely warnings of the
Weather Service, the loss of life was over 1,300 people. Two people were killed in Northern Virginia as a result
of the accompanying tornadoes which struck the area.
APPROXIMATE LOCATION OF THE CENTER OF HURRICANE DAVID
DATE
TIME
LATITUDE
LONGITUDE
WIND SPEED (MPH)
8/26
6 am
11.7° N
45.5° W
35
8/27
6 am
11.8° N
49.0° W
75
.
8/28
6 am
12.7° N
55.3° W
130
.
8/29
6am
14.5° N
60.3° W
140
8/30
6am
16.4° N
65.2° W
150
8/31
6am
17.3° N
69.2° W
150
9/1
6am
20.0° N
72.7° W
110
9/2
6am
22.5° N
76.2° W
75
9/3
6am
25.7° N
79.5° W
100
.
9/4
6am
29.6° N
80.8° W
90
.
9/5
6am
34.1° N
80.5° W
65
9/6
6am
40.5° N
77.5° W
45
9/7
6am
48.0° N
63.0° W
45
.
.
.
In September of 1985, it once again appeared ominous as Hurricane Gloria moved up the east coast of the
United States. The more intense portions of the storm remained offshore longer than predicted, finally hitting
land around the eastern shore of Maryland and again on central Long Island, N.Y.
APPROXIMATE LOCATION OF THE CENTER OF HURRICANE GLORIA
DATE
TIME
LATITUDE
LONGITUDE
WIND SPEED (MPH)
9/22
9am
17.8° N
59.4° W
75
9/22
9pm
19.1° N
60.4° W
75
9/23
9am
20.4° N
65.0° W
75
9/23
6pm
21.3° N
68.1° W
85
.
9/24
6am
22.1° N
69.5° W
110
.
9/24
3pm
23.4° N
70.4° W
125
.
9/25
12 am
24.8° N
72.0° W
156
9/25
9 am
25.9° N
74.4° W
150
.
9/25
9 pm
28.3° N
75.5° W
135
.
9/26
9 am
30.1° N
75.8° W
130
9/26
6 pm
31.9° N
75.8° W
130
.
9/26
9 pm
33.5° N
75.7° W
130
.
9/27
2 am
35.4° N
75.2° W
130
9/27
6 am
37.1° N
75.2° W
130
9/27
8 am
38.2° N
74.7° W
130
9/27
10 am
39.1° N
73.9° W
120
9/27
12 pm
40.5° N
72.5° W
100
9/27
2 pm
42.0° N
71.5° W
100
9/27
6 pm
43.9° N
71.3° W
75
LAB:HURRICANE DAVID/HURRICANE GLORIA
LAB:HURRICANE DAVID/HURRICANE GLORIA
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