Tracking Hurricane Andrew - Lab

TRACKING HURRICANE ANDREW - LAB

LEARNING OBJECTIVES

·  Use latitude and longitude coordinates to plot locations on a map.

·  Compare and contrast weather advisories such as “hurricane watch” and “hurricane warning”.

·  Describe the conditions necessary for a hurricane to develop and how it dies out.

BACKGROUND INFORMATION

As the Northeast Trade Winds blow a hot, dry air mass (cT – continental tropical) from the Sahara Desert (Africa) over the Atlantic Ocean, the sand and dust in the air act as condensation nuclei. The warm water in the Atlantic Ocean is constantly evaporating, and the water vapor in the air is then able to attach to the sand/dust and change into liquid water droplets, forming clouds. Because the warm air is rising and the moisture continues to increase, the air mass (now an mT – maritime tropical) can sometimes turn into a large Low-pressure storm system, called a Tropical Depression. If the Tropical Depression strengthens and gets larger, it becomes a Tropical Storm. The Northeast Trade Winds continue to move the storm westward across the Atlantic Ocean towards North America. Most storms will eventually catch the Prevailing Westerlies, which turns and moves them to the Northeast.

Although all Atlantic Ocean Tropical Storms develop this way, only a few of them each year intensify into Hurricanes. The “Atlantic Hurricane Season” runs from June 1st to November 30th each year, when the ocean water near the Equator is at least 82°F. During this time, Tropical Storms can sometimes strengthen enough to become a hurricane. On August 16, 1992, Hurricane Andrew formed in the Atlantic and proved to be one of the most intense and catastrophic hurricanes in recorded history.

The deadliest part of a hurricane is the storm surge - a rising of sea level caused by the winds and low air pressures created by a hurricane. Storm surges can reach shore up to 12 hours before the edge of the hurricane makes landfall, and can raise sea level up to 30 feet! The calm eye of the hurricane can be up to 40 miles wide, and the sinking air inside creates a clear view of the sky. The eye wall is a ring of tall thunderstorms around the eye that produces heavy rains and the strongest winds.

The death of a hurricane occurs when it loses its source of moisture. When a hurricane makes landfall, it begins to die out because of the lack of warm water which helps fuel them. Water at higher Latitudes (much cooler than water near the Equator) can also cause a hurricane to dissipate.

VOCABULARY

Tropical Depression: a Low-Pressure storm system of clouds and thunderstorms with winds up to 38 mph.

Tropical Storm: a Tropical Depression with sustained winds of 39-73 mph.

Hurricane: a Tropical Storm with sustained winds of 74 mph or greater. Hurricanes are categorized by their winds speeds; Category 1 is the weakest, Category 5 is the strongest.

TRACKING HURRICANE ANDREW - LAB

PROCEDURES

Part 1: CLASSIFYING – Determining the status of the storm

1)  Using the Wind Speed column in the “Hurricane Andrew Data Table” and the Saffir/Simpson Scale on this page, determine the status of the storm as either a Tropical Storm or a Hurricane (# 1-5). Fill this information in the last column of the Data Table.

Part 2: TRACKING – Plotting Latitude and Longitude of the Storm

2)  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 for each day & time. As you plot each point, label it with the date and time. For example: August 21, 03:00, is labeled “21/03” and August 21, 09:00 = “21/09.”

3)  Develop a color-coded key to represent the status of the storm at each data point. Use 5 different colors. Create a key at the bottom of your map. (Example: Blue = Tropical Storm, Green = Category 1 Hurricane, Orange = Category 2 Hurricane, etc.).

4)  Connect the points you plotted on your map with the correct colored pencil for each status of the hurricane.

5)  On your map, circle the points where the eye of the Hurricane first made landfall.

Part 3: GRAPHING – Wind Speed & Air Pressure

(You will plot two different sets of data on the same graph)

6)  Use a colored pencil to plot the data for Hurricane Andrew’s WIND SPEED vs. TIME on the graph, using the values for Wind Speed on the left side of the graph. Connect the points with a smooth curve.

7)  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 right side of the graph) Connect the points with a smooth curve.

Name: ______Date: ______Block: ______

TRACKING HURRICANE ANDREW - LAB

SUMMARY AND CONCLUSIONS

Use the Background information, your data, and the tracking map you created to help you answer the following questions.

1)  What is the difference between a Tropical Storm and a Hurricane? ______

2)  What kind of Pressure System (High or Low) is a Hurricane? ______

3)  What is the rotation pattern of wind in a Hurricane? CLOCKWISE COUNTER-CLOCKWISE

4)  Each year, what are the official dates for the “Atlantic Hurricane Season”? ______

5)  Based on your answer to #2, why do you think Hurricanes can’t form during Winter and Spring in the Northern Hemisphere? ______

6)  At what date and time did Andrew officially become a Hurricane? ______

7)  Look at the Saffir/Simpson Scale. What is the relationship between the Wind Speed and Storm Surge of a Hurricane? (use “increases” and “decreases”) ______

8)  Look at your graph. What is the relationship between Air Pressure and Wind Speed in hurricanes? (use “increases” and “decreases”) ______

______

9)  Between August 24, 15:00 and August 26, 3:00, the wind speed for Hurricane Andrew remained constant. Over what body of water was Andrew located during this time? ______

10) What is the deadliest part of a Hurricane? ______

11) Which global winds moved Hurricane Andrew across the Atlantic Ocean? ______

12) On August 25th, Hurricane Andrew starting turning to the North. Which global winds are responsible for Andrew’s change in direction? ______

13) How did the Wind Speed change after Andrew made landfall on August 26th? INCREASED DECREASED

14) How did the Air Pressure change after Andrew made landfall on August 26th? INCREASED DECREASED

15) Why did the Wind Speed and Air Pressure both change on August 26th? ______