HURRICANE ANDREW TRACKING INVESTIGATION
Objectives:
 Determine the strength of a hurricane using the Saffir/Simpson scale.
 Plot latitude and longitude coordinates on a map.
 Graph Wind Speed vs. Air Pressure
 Describe the conditions necessary for a hurricane to develop and how it dies out.
Introduction:
Like other Atlantic hurricanes, Andrew started as a low-pressure system in the tropics off the west coast of
Africa. Warm water and moisture-laden air supplied the energy for it to strengthen into an ordinary and
average tropical storm. Surface winds began to move the storm westward.
Although all tropical storms form and develop in this way, only a few intensify into hurricane. Most encounter
upper air winds moving in the opposite direction as the surface winds. As a result, these storms weaken and
soon die out. Tropical Storm Andrew, on the other hand, encountered upper air winds moving in the same
direction as the surface winds. These reinforcing winds caused Andrew to quickly strengthen into an
unusually powerful hurricane. Hurricane Andrew is only the third Category 5 hurricane to impact the United
States in recent history. Andrew proved to be one of the most intense Atlantic hurricanes of the 20th century.
History and Basics:
Weather satellites collect latitude and longitude coordinates to allow people to plot the paths of hurricanes
and make predictions and advisories as to where they will make landfall. The National Hurricane Center tracks
the hurricanes and issues their best estimate as to when and where a hurricane will hit and possible intensity
levels.
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A tropical depression is an organized system of clouds and thunderstorms with a defined surface
circulation and maximum sustained winds of 38 miles per hour.
A tropical storm has maximum sustained winds of 39-73 mph.
A hurricane has a well-defined surface circulation with sustained winds of 74 mph or greater and are
categorized by their winds speeds. Category 1 is the weakest and Category 5 is the strongest.
Hurricanes gather heat and energy through contact with warm ocean waters. The air over the water becomes
warm & humid which makes the air rise creating a very low pressure system.
The “death” of a hurricane results from the loss of moisture and warm water which happens during landfall.
Land is cooler & drier which stops the air from rising and increases the pressure. Also over land, winds slow
due to friction with the land surface
Hurricane Naming:
Prior to 1953, hurricanes were named by where they hit or their coordinates. In 1953, hurricanes began having
female names to help identify them in tropical waters, especially when there were multiple storms occurring
simultaneously. It wasn’t until 1979 that the hurricanes began alternating between male and female names in
alphabetical order in a six-year rotating list. These names are used repeatedly unless they are retired due to
substantial damage or death.
Throughout Virginia’s history, over 69 eyes of cyclones have passed over the state and 11 have made landfall
within 60 miles of Virginia’s coasts.
PROCEDURES: PLEASE READ AND FOLLOW THE INSTRUCTIONS CAREFULLY.
PART I: Complete the “STATUS” Column in the Hurricane Andrew Data Table
1. Using the Wind speeds on the Data Table and the Saffir/Simpson Scale below, determine the status of the storm
either a Tropical Storm or a Hurricane + Category. Fill in this information in the last column of the Data Table. (Two
examples are done for you.)
PART II: Graphing the Wind Speed & Graphing the Air Pressure
 You will plot two different sets of data on the same graph!
2. Use a colored pencil to plot the data for Hurricane Andrew’s WIND SPEED vs. TIME on the Graph. Connect the
points with a smooth curve.
3. Use a different colored pencil to plot the data for the hurricane’s AIR PRESSURE vs. TIME on the same graph.
(The scale for air pressure is on the other side across from wind speed.) Connect the points with a smooth curve.
Part III: Tracking the Storm – Latitude and Longitude
4. Using the Hurricane Andrew Data Table, plot the track of Hurricane Andrew on the Map by marking a point at the
correct latitude and longitude given. (The first few points are plotted for you)
5. Label each point you have plotted with the date and the time. Notice the times are on a 24-hour clock.
Example: the 1st point for August 21, 03:00 hrs, should be labeled “21/03.” August 21, 09:00 hrs = “21/09.”
6. Develop a colored coded key to represent the status of the storm and connect the points to track the storm. You
will use five different colors of your choice. Fill in the key in the margin of the map.
Example: Blue = Tropical Storm, Green = Category 1 Hurricane, and so on. Connect the points when it was a tropical
storm in blue, connects the points when it was a category 1 in green...
Part IV: Landfall Times
7. Look at the map where you plotted the track of the Hurricane. Circle the points where the Hurricane touches
land.
8. Find on your Wind Speed vs. Air Pressure Graph the date and times the landfall occurred. Circle those points on
the graph. Notice how landfall affects the Wind Speed and Air Pressure.
SAFFIR/SIMPSON SCALE
HURRICANE ANDREW DATA TABLE
DATE
Aug 21
Aug 22
Aug 23
Aug 24
Aug 25
Aug 26
TIME
LATITUDE
03:00 hrs
09:00 hrs
15:00 hrs
21:00 hrs
03:00 hrs
09:00 hrs
15:00 hrs
21:00 hrs
03:00 hrs
09:00 hrs
15:00 hrs
21:00 hrs
03:00 hrs
09:00 hrs
15:00 hrs
21:00 hrs
03:00 hrs
09:00 hrs
15:00 hrs
21:00 hrs
03:00 hrs
09:00 hrs
15:00 hrs
21:00 hrs
o
23.7 N
24.3o N
24.7o N
25.2o N
25.6o N
25.8o N
25.9o N
25.9o N
25.6o N
25.5o N
25.4o N
25.4o N
25.4o N
25.4o N
25.7o N
25.8o N
26.3o N
26.8o N
27.5o N
28.2o N
29.0o N
29.7o N
30.5o N
30.6o N
LONGITUDE
PRESSURE
WIND SPEED
STATUS
1013 mb
1006 mb
1007 mb
1004 mb
1001 mb
994 mb
974 mb
974 mb
959 mb
951 mb
930 mb
923 mb
931 mb
932 mb
945 mb
945 mb
945 mb
949 mb
944 mb
937 mb
940 mb
954 mb
987 mb
991 mb
50 mph
50 mph
60 mph
60 mph
65 mph
75 mph
90 mph
110 mph
125 mph
150 mph
165 mph
175 mph
160 mph
150 mph
150 mph
160 mph
150 mph
140 mph
140 mph
140 mph
135 mph
115 mph
90 mph
60 mph
Tropical Storm
o
63.0 W
63.7o W
64.6o W
65.4o W
66.5o W
67.5o W
69.0o W
70.4o W
71.9o W
73.4o W
75.0o W
76.5o W
78.1o W
80.3o W
82.1o W
83.9o W
85.7o W
87.0o W
89.2o W
90.2o W
91.1o W
91.7o W
91.6o W
91.6o W
Hurricane - 1
The Relationship between Wind Speed and Air Pressure over Time.
Date & Time
Name: _________________________________________ Date: ________________________ Block: ______
Hurricane Andrew – Analysis and Conclusions:
 watch your use of “it” – don’t start sentences with “because” – don’t abbreviate
 use “increases” or “decreases” to describe relationships when necessary
1. What is the lowest air pressure recorded of Hurricane Andrew? ____________________________________________
2. Where was Hurricane Andrew when it reached its lowest air pressure? [ over land
/
over water ]
3. How did Hurricane Andrew’s air pressure change after the hurricane hit land? [ increase / decrease ]
4. Why does lower air pressure occur over water where hurricanes form? ______________________________________
______________________________________________________________________________________________
5. How did Hurricane Andrew’s wind speed change after the hurricane hit land? [ increase / decrease ]
6. Look at your map, where was Hurricane Andrew located between August 24, 15:00 and August 26, 3:00?
[ over land
/
over water ] Explain how this affected the wind speed during the same period of time?
______________________________________________________________________________________________
7. According to your graph, what is the general relationship between air pressure and wind speed?
______________________________________________________________________________________________
Base your answers to questions #8-10 on the following:
Compare the length of the hurricane track between the points plotted for Aug 24, 15:00 and Aug 25, 15:00, to the length of
the track between Aug 25, 15:00 and Aug 26, 15:00.
8. During which time period did the hurricane move faster? [ 24/15–25/15 or 25/15–26/15 ]
9. How can you tell? ________________________________________________________________________________
10. Why did the hurricane’s speed change?______________________________________________________________
11. A tropical storm officially becomes a hurricane when it attains speeds greater than 74 mph.
What date and time did Hurricane Andrew change from a tropical storm to a hurricane? ___________________________
12. What date and time did it change back to a tropical storm? _______________________________________________
Read the “Hurricane Formation” section on pg. 451 in the textbook. Then answer the following:
13. What must happen for a mild atmospheric disturbance (like a thunderstorm) to develop into a hurricane?
_________________________________________________________________________________________________
14. What “effect” causes what you determined above to happen? ____________________________________________
15. Why don’t hurricanes form at the equator? ___________________________________________________________
Look at your Global Winds map in your notes or the diagram on pg 423.
16. What winds are responsible for steering the hurricane from near the equator to the west? ______________________
17. On August 25th, Hurricane Andrew started to turn to the north and eventually would turn to the east. What winds are
responsible for Andrew’s change in direction?
___________________________________________________________
STORM STATUS KEY
Tropical Storm:
Category 1 Hurricane:
Category 2 Hurricane:
Category 3 Hurricane:
Category 4 Hurricane:
Category 5 Hurricane: