Southern AERA Quarterly Activity Bulletin of The South Carolina Department of Natural Resources-Southeast Regional Climate Center
Volume 3, No. 2
Hurricanes can be extremely dangerous storms. It is important to follow advice administered by emergency management agencies such as FEMA (Federal Emergency Management Agency). Many steps should be taken to help reduce the risk of danger if a hurricane should threaten your family. These should be taken before, during and after hurricane risk to ensure safety.
Before your area becomes threatened, it is important to make plans ahead of time, in case disaster strikes suddenly. Contact your local emergency management office or American Red Cross chapter, and ask them to send a copy of the community hurricane preparedness plan. The plan should include emergency shelters in your area as well as the quickest, safest evacuation routes. In addition, your family should have disaster supplies on hand. It should also be taken into consideration that although most people consider their family pet a part of their family, pets may not be allowed into emergency shelters. The local humane society will have information on what to do with your pet. The windows on your home also need to be protected. If you do not have permanent shutters, plywood panels should be cut to fit each window on your house.
During hurricane watches and warnings, it is very important for everyone to stay alert and take precautionary measures. Make sure that there is fuel in your car and that emergency supplies are on hand. Have a battery powered radio in case electricity is interrupted to listen to hurricane updates. Board up windows, bring lawn furniture, tools, and anything else that could blow away indoors. If officials direct everyone to evacuate, do so as quickly as possible! It is always better to be safe than sorry.
When a hurricane has ended, a new set of precautions must be observed. Damage may have occurred during the storm, and it is important to be aware of dangers that may exist. Keep listening to the radio for updates. Help anyone who may be injured. Drive only if you must. Avoid dangling and loose power lines. Beware of gas leaks, and if one is detected by smell or sound, turn off the main valve for the house and get out! Upon returning to your home, be careful of animals that may have been washed in by the storm. Take pictures for insurance purposes. Inspect for electrical and sewer damage. If you suspect pipes have been damaged, avoid drinking the water and call the water company. If the electrical system has been damaged, turn the electricity off at the circuit breaker.
For more detailed information on what to do if a hurricane should occur, look at the FEMA Fact Sheet at:
Atlantic Hurricanes in 1997
What is a tropical system?
A tropical system is a storm that forms over tropical waters. In the Atlantic, these storms develop mainly during the summer and fall making the dates of hurricane season June 1 - November 30. These storms occur primarily between these dates because warm ocean waters feed developing tropical systems. Warm water temperatures cause convection, which is the vertical movement of air in the atmosphere. Convection occurs because heat rises. As systems move inland, they usually "die" because warm water temperatures can no longer "drive" the storm.
History and Background
The name hurricane evolved from West Indian usage for violent storms in the Caribbean Sea and surrounding islands. Storms such as these are found in all major oceans except the South Atlantic. In the western Pacific in the Northern Hemisphere these same storms are called typhoons, and in other places are known as tropical cyclones. Hurricanes do not start out as the massive storms we know them to be, but as smaller storms. Tropical storms increase in organization as wind speed increases and central pressure decreases. When storms intensify, they are classified by their characteristics.
Stages of Development
The first stage of tropical system development is called a tropical disturbance. This type of storm is characterized by organized convection that is not associated with a front and maintains its identity for at least 24 hours. The next stage in tropical system development is tropical depression. Tropical depressions have wind speeds of 38 mph or less. In the next stage of development, tropical storm, the storm receives a name. Tropical storms have wind speeds reaching between 39-74 mph. The next and final stage of tropical system development is a hurricane, with wind speeds of 74 mph or greater. The winds of hurricanes have been known to reach 200 mph! Damage from these storms can be extensive. The southeastern portion of the United States has seen many hurricanes and the damage that they have done to both property and people.
Ana Bill Claudette Danny Erika Fabian Grace Henri Isabel Juan Kate Larry Mindy Nicholas Odette Peter Rose Sam Teresa Victor Wanda
What is Storm Surge?
One of the most damaging features of tropical storms is the storm surge. The storm surge is a wall of water created by high winds and pressure differences, and usually lasts for several hours. It causes the greatest amount of damage to low lying coastal areas. The storm surge is estimated by subtracting the height of the normal tide from the observed tide during the storm. The storm surge is even more damaging when it occurs during high tide. Storm surge causes intense flooding and accompanies wind damage during tropical systems. Since both strong winds and storm surge are so dangerous to people, a warning system has been developed that should be understood and followed for everyone's safety.
Hurricane Watches and Warnings
Hurricanes are monitored closely by meteorologists in order to determine their location and possible paths. When a hurricane could hit an area within a few days, a hurricane watch is issued. When a hurricane is likely to strike an area within 24 hours, a hurricane warning is issued. This warning system is designed so that residents of threatened areas are allowed enough time to evacuate and escape the danger of the oncoming hurricane. The importance of heeding the hurricane warning system is obvious. If the warnings are not followed, individuals are putting their lives in danger. Be smart and be prepared! Always be aware of a tropical systems's location and pay close attention to any watches or warnings issued.
1. What are the dates of hurricane season?
2. What "feeds" hurricanes?
3. Why don't hurricanes occur all year long?
4. Why does convection occur?
5. Why do hurricanes generally not continue onto land?
6. Hurricane winds have been recorded as high as _______.
7. A tropical storm is not classified as a hurricane until wind speeds reach ______.
8. If before Hurricane Hugo, the normal high water height in Folly Beach, SC was 3 ft above mean sea level and during Hurricane Hugo reached a maximum of 23 feet, what was the storm surge?
9. When is storm surge the most dangerous?
10. When is a hurricane watch issued?
USING TABLE 1, ANSWER THE FOLLOWING QUESTIONS
11. Which column has the most named storms?
12. Which column has the most intense hurricanes?
13. Do you think the 1997 hurricane season is predicted to be below average, above average, or average?
Southern AER is a quarterly publication of the Southeast Regional Climate Center. Funding is provided by a grant from the National Oceanic and Atmospheric Administration.
Internet Resources On Hurricanes