Name: ___________________________________________________ period: _______ date: ______________
Introduction
Hurricane season runs from June 1 to November 30 every year as thunderstorms form over the warm
moist air of the Atlantic Ocean. Sometimes these thunderstorms come across the ocean, intensifying before
they run into the islands of the Caribbean, and coastal regions of the southeastern United States. In 1989,
Hurricane Hugo devastated North Carolina and was one of the worst the U.S. had experienced in 20 years. In
1996, Hurricane Fran caused a lot of wind damage and flooding in the Triangle area. Hurricanes Isabel and
Charley tore through North Carolina’s Outer Banks in 2003 and 2004. Throughout North Carolina’s history,
approximately 28 storms have made direct landfall (http://www.nc-climate.ncsu.edu/climate/hurricane.php).
The 2005 Hurricane season was the most active on record resulting in 27 storms, although none passed through
North Carolina.
Like other Atlantic Hurricanes, Katrina started as a low-pressure system in the tropics off the west coast
of Africa. Warm water and humid 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 this way, only a few intensify into hurricanes. Most tropical storms encounter upper atmospheric winds
moving in the opposite direction as the surface winds, and as a result, these storms weaken and die out. Tropical
storm Katrina, on the other hand, encountered upper atmospheric winds moving in the same direction as the
surface winds. These winds reinforced each other, causing Katrina to quickly strengthen into an unusually
powerful hurricane. Katrina was the sixth most powerful Atlantic hurricane ever recorded, and the third most
destructive hurricane to make landfall in the United States. Katrina’s storm surge flooded 80% of New Orleans
as the levees were breached, caused at least 1836 deaths, and an estimated $81.2 billion dollars in damages.
Procedure
1. Use the Hurricane Katrina Data table to plot the track of Hurricane Katrina on the map provided. Start with
the data for August 24, 00:00 EDT.
2. Connect the points you have plotted, and draw an arrowhead to indicate the direction of Hurricane Katrina’s
movement.
3. Label each noon point you have plotted with the date and time. For example, the data point for August 24,
12:00, should be labeled “24/12” and the point for August 25, 12:00, should be labeled “25/12.”
4. Use a colored pencil to plot the data for Hurricane Katrina’s wind speed versus time on the graph provided.
Connect the data points with a smooth curve. Label the curve “Wind Speed.”
5. Use a second colored pencil to plot the data for the hurricane’s air pressure versus time on the same graph
as before. Connect the points with a smooth curve. Label the curve “Air Pressure.”
6. Use the hurricane track you plotted in step 1-3 to determine the landfall times for Florida and Louisiana.
Landfall occurs when the hurricane first passes over land. On your graph, use a third colored pencil and a
straight edge to draw vertical lines corresponding to the landfall times.
7. In a fourth color, draw a vertical line to indicate when Hurricane Katrina passed from Florida onto the water
of the Gulf of Mexico.
Hurricane Katrina Data Table
Time
(24-hour clock)
Latitude
(°N)
Longitude
(°W)
Wind Speed
(mph)
Air Pressure
(millibars)
Status
8/24/2005
00:00 EDT
12:00 EDT
23.4
24.5
75.7
76.5
35
40
1007
1006
Tropical Depression
Tropical Storm
8/25/2005
00:00 EDT
12:00 EDT
26.0
26.2
77.7
79
50
60
1000
994
Tropical Storm
Tropical Storm
8/26/2005
00:00 EDT
12:00 EDT
25.9
25.1
80.3
82.0
75
80
983
979
Hurricane-1
Hurricane-1
8/27/2005
00:00 EDT
12:00 EDT
24.6
24.4
83.3
84.7
105
115
959
942
Hurricane-2
Hurricane-3
8/28/2005
00:00 EDT
12:00 EDT
24.8
25.7
85.9
87.7
115
175
941
909
Hurricane-3
Hurricane-5
8/29/2005
00:00 EDT
12:00 EDT
27.2
29.5
89.2
89.6
160
125
905
923
Hurricane-5
Hurricane-3
8/30/2005
00:00 EDT
12:00 EDT
32.6
35.6
89.1
88.0
75
35
961
985
Tropical Storm
Tropical Depression
8/31/2005
00:00 EDT
38.6
85.3
30
994
Extratropical Storm
Date
Analysis & Conclusions
1. What is the difference between the highest and the lowest air pressure values given in the data table? Would
you expect this value to be more or less than the air pressure change across a typical Middle-Latitude
Cyclone?
2. Between August 27, 12:00 EDT, and August 28, 00:00 EDT, the wind speed for Hurricane Katrina
remained essentially the same. Where was Hurricane Katrina during this period of time? What did this area
provide to strengthen the storm?
3. According to your graph, what is the general relationship between air pressure and wind speed?
4. How did Hurricane Katrina’s air pressure and winds speed change with each landfall?
5. How did Hurricane Katrina’s air pressure and wind speed change as it moved across the Gulf of Mexico?
6. Explain how air pressure and wind speed are affected by the surface over which a hurricane moves.
7. Compare the distance moved between the points plotted for August, 27, 18:00 EDT and August 28, 18:00
EDT to the distance moved between August 28, 18:00 EDT, and August, 29, 18:00 EDT. During which 24hour time period did the hurricane move farther? What would account for this difference?
8. A tropical storm officially becomes a hurricane when it attains sustained wind speeds of 74 mph (119
km/hr). When did Katrina change from a tropical storm to a hurricane? When did it change back into a
tropical storm?