Hurricanes

As a long-time resident of Coastal South Carolina, from June to October my daily routine includes tuning into the tropical update. My husband calls it my hurricane watch, I call it prudence.

I grew up in landlocked Minnesota, but moved to South Carolina in the 1980's. The local news broadcasts talked about hurricane preparedness, but I grew up with storm warnings and tornado watches. A hurricane couldn't be any worse than that.

I was wrong.

When it was determined that Hurricane Hugo would hit Charleston, SC, city officials recommended evacuation. Chris and I both worked in the medical field so leaving wasn't an option. It didn't matter. We lived in a suburb on the west side of Charleston. We would be safe.

We rode out the storm in our home in Summerville. There were many times during that terrifying night that I wondered if we would survive to see the dawn. Since that night I have made a point of learning all I could about the tropical depressions and storms likely to evolve into a hurricane, how to track a storm, how to minimize the inevitable damage, what to take and what to leave behind.

It begins with an area of low atmospheric pressure. If the conditions are favorable and the water temperature at least 26.5 oC (79.7 oF), it can develop into a tropical depression. Tropical depressions are common and most dissipate without notice, but some develop into a cyclone.

Warm air rises. When it reaches higher elevations, the temperature of the air begins to drop. A tremendous amount of energy is released as the water vapor in the air condenses. The warm air rises, cools, and then drops, causing a positive feedback loop. The disparity between the rising warm air and the dropping cool air also feeds the convection currents. Wind speeds pick up. The faster the winds, the lower the air pressure which in turn causes more evaporation at the water's surface. A cyclone has formed.

The rotation of the Earth causes the system to spin. It will spen clockwise in the southern hemisphere and counter-clockwise in the northern hemisphere. This is known as the Coriolis Effect. The system is fed by the energy in the warm water and will continue to grow as long as the conditions are favorable.

What started out as a tropical depression may or may not evolve into a hurricane. The storm is classified by its wind speed.

A Tropical Depression will have swirling clouds, rain, and wind speeds of less than 38 mph (61.2 kph). Its not organized enough to have an eye and lacks the obvious spiral formation of stronger storms.

A Tropical Storm will have wind speeds between 39 and 73 mph (54.7 to 117.5 kph). The storm is named at this time. At this point the storm is started to develop a distinctive cyclonic shape. Like the tropical depression, it still doesn't have a distinct eye.

Hurricanes have wind speeds greater than 74 mph (119 kph). They are rated using the Saffir-Simpson Scale. An eye has formed and there is a distinct eye-wall. The eye and the cyclonic structure of the storm can easily be seen with satellite images.

Eye: The eye is an area of sinking air at the center of the circulation. In an intense storm the weather within the eye is usually calm and free of clouds. Weaker storms may have cloud cover over the eye. The eye is usually circular in shape with a diameter as small as 2 miles (3 km) and as large as 230 miles (370 km).

Eye wall: The eye wall is a circle of thunderstorms surrounding the eye. The greatest wind speeds and the heaviest rains occur within the band comprising the eye wall. When a hurricane is at its peak, the eye wall is usually 6.2 miles (10 km) to 16 miles (25 km) wide.

As the inner wall weakens, the next rain band pushes inward and takes its place. There is a variation in strength as the storm makes its way through the cycle. Once the eye wall is replaced, the storm regains its original intensity.

Rain Bands: Rain bands are bands of showers and thunderstorms that spiral outward from the center of the storm. The bands are accompanied with heavy downpours and wind gusts. There's usually brief stretches of calmer weather between the bands.

The Saffir-Simpson Hurricane Scale is the scale used to classify tropical cyclones that have reached hurricane status. To be classified as a hurricane, the storm must have sustained winds of at least 74 mph (119 km/hr). the scale's primary purpose is to measure potential damage and flooding. It is used for describing storms that form in the Atlantic Ocean and in the northern Pacific Ocean east of the International Date Line. The scale goes from Category 1 to Category 5 with Category 5 being the worst. Hurricane Hugo was a 3 when it blew into Charleston. I can't imagine what a Catagory 5 would be like.

Category 1 Hurricane

Wind Speed
74-95 mph
(119 to 153 kph)

Effects
Storm surge 4 to 5 ft (1.2 to 1.5m) above the normal
Some flooding
Little or no structural damage

Category 2 Hurricane

Wind Speed
96 to 110 mph
(155 to 177 kph)

Effects
Storm surge 6 to 8 ft (1.8 to 2.4 m) above normal
Trees down
Roof damage (shingles ripped off)

Category 3 Hurricane

Wind Speed
111 to 130 mph
(178. to 209 kph)

Effects
Storm surge 9 to 12 ft (2.7 to 3.7m) above normal
Structural Damage to houses
Mobile homes destroyed
Severe flooding

Category 4 Hurricane

Wind Speed
131 to 154 mph
(210 to 247.8 kph)

Effects
Storm surge 13 to 18 ft (4-5.5m) above normal
Severe flooding inland
Some roofs ripped off
Major structural damage

Category 5 Hurricane

Wind Speed
Greater than 155 mph
(greater than 249.4 kph)

Effects
Storm surge at least 18 ft (5.5m) above normal
Severe flooding further inland
Serious damage to most wooden structures

While the rating of a hurricane is based on the wind speed, they can vary in size. Some are compact with just a few bands, but others can be hundreds of miles wide. Tracking maps predict where the eye will come to land, but don't use that as your sole criteria when assessing your risks. Hurricane Floyd came to land in North Carolina but the affects were felt all along the eastern seaboard from South Carolina to Virginia.

Hurricanes bring strong winds, but the winds are not the only force to be reckoned with. Hurricane Andrew was responsible for thirty million dollars in property damage and over 50 deaths. The wind was a big part of it, but the torrential rains, storm surge, flooding, rip tides, and tornados did their part as well.

A storm surge is primarily caused by high winds pushing on the surface of the water. The wind causes the water to "pile up". The low pressure associated with the eye of the storm compounds the problem, bringing the water levels even higher. Flooding is a given. If the hurricane crosses onto land at high tide, the flooding can be intense going further inland than expected. Torential rains and flooding were a big probem with Hurricane Floyd.

With storm surges and hurricanes we are bound to have riptides as well. A riptide is a strong current flowing outward at the surface of the water. They are extremely dangerous. They will literally drag a swimmer away from the beach. Rip currents are responsible for over 100 deaths a year in the United States alone.

There are some bodies of water that will always have riptides but a tropical store sitting offshore will cause riptides in areas that don't routinely have them. Everytime a hurricane or tropical storm passes close to our shores, surfers are on the water. They use the riptide to carry them out to catch the wave. They understand the risks but ignore the warnings. Faced with such foolishness all we can do is pray.

Hurricanes can also spawn tornados, but looking at the aftermath of a hurricane, its difficult to tell what damage was caused by the wind and what was caused by tornados. During Hugo, several of the trees in our backyard were twisted around before they snapped. Was it a tornado? We will never know.

Hurricane season officially started on June 1st. As the energy needed to sustain a hurricane comes from the water, it is rare for one to strike this far up the coast this early in the season. As summer progresses, the water temperature rises. Hurricanes track farther and farther north. For Charleston, South Carolina, peak hurricane season is September. If a hurricane forms early in the season, it is more likely to track further south across Florida or along the Gulf of Mexico. The key word is likely. It is not a guarentee. Prepare early. You'll worry less.

There are several things that should be done at the beginning of the season rather than wait for an emminant strike. You will have enough things to worry about then without adding avoidable worries to the mix.

Take a good hard look at your yard. Are your trees riddled with dead branches and limbs? A strong wind will likely bring the dead limbs down. During a hurricane they may become projectiles adding to the inevitable damage. Eliminate the problem by removing the limbs now rather than later.

Is your garage cleaned out? Can you park your car in the garage or is it full of broken furnature, lawnmowers, and toys? Cars left in the driveway or on the street are vunerable to falling trees and projectiles. If you drive an older car and just carry libability insurance, you could be left with nothing.

Is your pantry stocked? Some people fill a box with can goods and store it in a closet, I don't. I stock up on the nonparrishable foods we routinely use rather than buy "hurricane supplies." The key word is nonparrishable. We routinely snack on mixed nuts. Rather than 1 extra can in the pantry I will have 3. Foods that do not require preparation or refrigeration are good choices. We were without power for 8 days after Hugo. We ate a lot of peanut butter and crackers, trail mix, and tuna fish from the can.

Another thing to consider is paper products. Keep extra paper towels and toilet paper on hand. Running out of either one of them can be frustrating. Keep your picnic supplies stocked. You will have enough to do after the storm without washing dishes in cold water. (If you have water.) We did, but many of our friends did not.

Speaking of water... Drinking water is vital. Once a storm watch turns to a warning (if not before) the stores will be out of bottled water, batteries, and ice. If you don't have them before the first warning is posted, you may be out of luck.

Ice. Ice cubes are great for cooling a drink but they don't last long in a cooler. I make 2 or 3 large chunks of ice and store them in the bottom of my deep freeze. I also fill bags with ice cubes. Neither project takes long and if you need them, you'll be glad you took the time.

Don't forget the First Aid Kit. We are in and out of our First Aid Kit often but rarely remember to restock it. Now would be a good time to do that.

Know where you will go if you need to evacuate. Do you have friends you can stay with? Do you know how to get to their place? If not, make sure you have the name and pnone number of several hotels in the town you are heading toward. A map of the area would be good as well. You may be forced off the main road and need to find your way through "uncharted territory."

Give some thought to what you are willing to live without and what you consider vital. If you have the essentials on hand, it will be one less thing to worry about in the days before the storm.

There are four weather alerts for tropical storms and hurricanes.

Tropical-storm Watch

A tropical-storm watch is issued when sustained winds from 39 to 73 mph are possible in your areas in the next 36 hours.

Tropical-storm Warning

A tropical-storm warning is issued when sustained winds from 39 to 73 hours is likely in your area within the next 24 hours.

Hurricane Watch

A hurricane watch is issued when hurricane conditions are possible in your area within the next 36 hours.

Hurricane Warning

A hurricane warning is issued when hurricane conditions are likely in your area within the next 24 hours.

If your home is in the path of a Hurricane, pay close attention to what your local government officials are recommending. If you are in an area designated for manditory evacuation, don't defy authority. The government doesn't make the call lightly. If they are calling for a manditory evacuation, there's good reason for it.

If you live in an area where evacuation is recommended, the final decision is up to you. People with small children or infants, the elderly, and people with medical conditions should heed the warning.

It is not a decision to be made lightly. In the days before Hurricane Floyd hit North Carolina, it was expected to hit Charleston. It was 48 hours out and already a Category 5 hurricane. My husband was scheduled to work up to and through the storm. The decision to stay or leave fell to my shoulders. With 2 elementary school age children, a dog, and a cat, the choice was easy. The huge trees up close to the house factored in as well. Staying at the house would not be safe. Knowing what we needed to take made it easier. We were on the road within an hour.

The decision to stay or leave needs to be made early. Many coastal cities have limited exit routes. In the 24 hours prior to Hugo, Interstate 26 was bumper-to-bumper. Cars overheated and many ran out of gas while sitting in traffic. If you decide to stay, don't change your mind at the last minute. At that point you may not be able to leave.

Once the decision to stay has been made, its time to get busy. There are several things that will need to be done before the hurricane makes landfall. If you work and your boss expects you to be at your desk, the allotted time to prepare will be limited. Even if you are not a listmaker, I recommend that you do. Its too easy in the rush to forget something important.

1. Recheck your supplies. If you did what you were supposed to do, you would already have the basics. At this point the stores will be crowded and the shelves bare.

flashlights
Batteries
Candles
Battery operated radio
First aid kit
Nonparrishable food
Manual can opener
Ice
Drinking water

2. Gas up the car. The pumps may or may not be working. Its better to be safe, especially if you are expected to return to work once the storm has passed through.

3. Wash clothes. We were without electricity for 7 days. If the hampers are already full, you may be left with nothing to wear.

4. Prescriptions. Make sure you have enough of your prescription medications to last through the storm and for several days afterwards.

5. Recharge your cell phone.

6. Be ready to document any damage. If you have a digital camera, make sure the battery is fully charged. If you have a regular camera, make sure you have plenty of film. Not only will family living across the country want to see what happened, the insurance company may want a visual record of damages.

7. Check on Family and Friends. If you have family in the area, check in with them. Know who is staying and who is going. You don't want to frantically search through rubble for a loved one only to find they are lounging on a friend's deck 2 states away. It would be annoying.

8. Birdfeeders and Yard Art. Take down birdfeeders, chimes and other yard ornaments. Secure your lawn and deck chairs. Lightweight and even heavy objects left outside can become projectiles.

9. Say a prayer and get some rest. You will have several long, difficult days ahead of you.

Whether you "Batten down the Hatches" or seek shelter inland, keep one thing in mind. Hurricanes are a force of nature not to be trifled with. I love my home and if I lost it I would be devastated, but it's not worth my life. Houses can be rebuilt, fences and gates repaired. Even my turtle shaped watering pot can be replaced.

Take care and make wise decisions, not emotional ones. If its not safe to stay, don't stay. Don't become one of the casualties.

Be Safe!

The 2008 Hurricane Season started early with Tropical Storm Arthur forming the end of May. It was a busy season and the third most costly on record. There was a major storm to deal with every month with tropical storms sliding in between them.

Hurricane Ike was the most destructive storm of the season. It devastated Cuba and then making landfall near Galveston, Texas as a category two storm.

Spring has arrived and we will be facing another Hurricane Season soon.

Be ready.

Kolberg, J. 2004. Organize for Disaster. Squall Press, Decatur, GA.

Hurricanes, Online Meteorology Guide
Horrific Hurricanes
How Stuff Works: Hurricanes