What is a tropical storm?
- A tropical storm is a fierce storm with strong winds rotating around a center of low pressure.
- When conditions worsen, a tropical storm can be classified as a hurricane.
- Hurricane season is June 1 to November 30.
- It's rare, but Atlantic hurricanes have formed as early as March or as late as December.
- Major hurricanes (Category 3 and above) hit almost exclusively between August and October.
- Hurricanes have sustained, maximum wind speeds of 73 miles-per-hour or greater.
- The word "hurricane" is regional -- applying to the north Atlantic Ocean, parts of the northeast Pacific Ocean and parts of the south Pacific Ocean.
- A typhoon is the same thing occurring in the northwest Pacific Ocean.
- Hurricanes rotate counter-clockwise in the northern hemisphere.
What determines a storm's strength and path?
- Generally, warmer ocean water leads to stronger storms.
- Hurricanes are steered by ocean currents, atmospheric pressures and their own winds.
- One expert says hurricane movement is like the path of a leaf in a stream.
- Where do hurricanes usually hit?
- 36 percent of all American hurricanes hit Florida.
- 76 percent of Category 4 or higher hurricanes hit Florida or Texas.
Deadliest hurricanes in American history:
- Galveston, 1900. A Category 4 hurricane left 8,000 people or more dead.
- South Louisiana, 2005 Hurricane Katrina, a Category 5 storm killed more than 1,800 people
- Southeast Florida, 1928. A Category 4 storm killed 1836 people.
- Great Miami Hurricane, 1926. Category 4 devastated Miami, killing at least 800 people.
- Florida Keys/Southeast Texas, 1919. Some 600 people were killed by a Category 4 storm.
- New England, 1938. Category 3 hurricane killed about 600 people.
- Florida Keys "Labor Day Hurricane," 1935. Category 5 storm left 408 people dead.
- Hurricane Audrey. Southwest Louisiana/NW Texas, 1957. Category 4 storm killed 390 people.
Costliest hurricanes in American history (Adjusted for inflation):
- Hurricane Katrina. Louisiana (especially New Orleans), 2005. Category 5 storm cost $108 billion
- Hurricane Andrew. Southeast Florida, 1992. Category 5 storm cost about $34 billion.
- Hurricane Hugo. South Carolina, 1989. Category 4 hurricane cost $9.7 billion.
- Hurricane Agnes. Southeast Florida, 1972. Category 1 storm cost $8.6 billion.
- Hurricane Betsy. Southeast Florida, 1965. Category 3 storm cost $8.5 billion.
- Hurricane Charley. Florida Gulf Coast. 2004. Category 4 cost an estimated $7.4 billion.
- Hurricane Camille. Mississippi/Louisiana, 1969. Category 5 cost $6.9 billion.
- Hurricane Jeanne. Florida, 2004. Category 2 cost estimated $6 billion or more.
- Hurricane Ivan. 2004. The strong Category 3 storm caused $7 billion in damage.
- Hurricane Frances. Central Florida, 2004, Category 2 cost an estimated $4.4 billion.
Category 4 and 5 storms:
Since 1900, just four Category 5 storms have hit the continental US. There have been 15 Category 4 storms in that time, including Hurricane Charley.
The last time the US was hit by two hurricanes of Category 4 or above in the same year was 1915. That year a Category 4 storm hit Galveston and another one hit New Orleans.
Category 5 storms since 1900 (in order of intensity):
- Hurricane Katrina hit Louisiana in 2005, killing more than 1,800 people.
- Unnamed storm hit Florida Keys in 1935, killing 408 people.
- Hurricane Camille hit Mississippi in 1969.
- Hurricane Andrew hit southeast Florida in 1992.
The categories are determined by the Saffir-Simpson Scale.
CATEGORY ONE: winds 74-95 mph (64-82 kt or 119-153 km/hr).
- Storm surge 4-5 feet above normal.
- No real damage to buildings or structures.
- Shrubs, loose signs and unanchored mobile homes may sustain some damage. Coastal flooding is possible.
CATEGORY TWO: winds 96-110 mph (83-95 kt or 154-177 km/hr).
- Storm surge 6-8 feet above normal.
- Considerable damage to shrubbery and trees as well as to mobile homes, poorly constructed signs and piers.
- Coastal and low-lying escape routes flood 2-4 hours before arrival of the hurricane center.
CATEGORY THREE: winds 111-130 mph (96-113 kt or 178-209 km/hr).
- Storm surge generally 9-12 ft above normal. Some damage to small residences.
- Some large trees blown down. Some mobile homes and poorly constructed signs are destroyed.
- Flooding near the coast destroys smaller structures.
- Terrain lower than 5 ft above sea level may be flooded inland 8 miles (13 km) or more.
CATEGORY FOUR: winds 131-155 mph (114-135 kt or 210-249 km/hr).
- Storm surge generally 13-18 ft above normal.
- Roofs destroyed on many buildings and residences, Shrubs, trees, and all signs are blown down. Complete destruction of mobile homes. Extensive damage to doors and windows.
- Terrain lower than 10 ft above sea level may be flooded.
CATEGORY FIVE: winds greater than 155 mph (135 kt or 249 km/hr).
- Storm surge generally greater than 18 ft above normal.
- Complete roof failure on many residences and industrial buildings. Some buildings completely destroyed. All shrubs, trees, and signs blown down. Complete destruction of mobile homes.
- Major damage to lower floors of all structures located less than 15 ft above sea level and within 500 yards of the shoreline.
- Massive evacuation of residential areas on low ground within 5-10 miles (8-16 km) of the shoreline may be required.