"Preparation through education is less costly than learning through tragedy."
- BILL PROENZA, DIRECTOR
NATIONAL HURRICANE CENTER
How can I protect myself from a hurricane?
What is a Hurricane?
A
hurricane is a type of tropical cyclone, the generic term for a low
pressure system that generally forms in the tropics. A typical cyclone
is accompanied by thunderstorms, and in the Northern Hemisphere, a
counterclockwise circulation of winds near the earth’s surface.
All Atlantic and Gulf of Mexico coastal areas are subject to
hurricanes or tropical storms. Parts of the Southwest United States and
the Pacific Coast experience heavy rains and floods each year from
hurricanes spawned off Mexico. The Atlantic hurricane season lasts from
June to November, with the peak season from mid-August to late October.
Hurricanes can cause catastrophic damage to coastlines and several
hundred miles inland. Winds can exceed 155 miles per hour. Hurricanes
and tropical storms can also spawn tornadoes and microbursts, create
storm surges along the coast, and cause extensive damage from heavy
rainfall.
Hurricanes are classified into five categories based on their wind
speed, central pressure, and damage potential (see chart). Category
Three and higher hurricanes are considered major hurricanes, though
Categories One and Two are still extremely dangerous and warrant your
full attention.
How are the Hurricane Categories Determined?
| Saffir-Simpson Hurricane Scale |
Scale Number
(Category) |
Sustained Winds
(MPH) |
Damage |
Storm Surge |
| 1 |
74-95 |
Minimal: Unanchored mobile homes,
vegetation and signs. |
4-5 feet |
| 2 |
96-110 |
Moderate: All mobile homes, roofs,
small crafts, flooding. |
6-8 feet |
| 3 |
111-130 |
Extensive: Small buildings, low-lying
roads cut off. |
9-12 feet |
| 4 |
131-155 |
Extreme: Roofs destroyed, trees
down, roads cut off, mobile homes
destroyed. Beach homes flooded. |
13-18 feet |
| 5 |
More than 155 |
Catastrophic: Most buildings
destroyed. Vegetation destroyed.
Major roads cut off. Homes flooded. |
Greater than 18 feet |
Hurricanes can produce widespread torrential rains. Floods are the
deadly and destructive result. Slow moving storms and tropical storms
moving into mountainous regions tend to produce especially heavy rain.
Excessive rain can trigger landslides or mud slides, especially in
mountainous regions. Flash flooding can occur due to intense rainfall.
Flooding on rivers and streams may persist for several days or more
after the storm.
Between 1970 and 1999, more people lost their lives from freshwater
inland flooding associated with land falling tropical cyclones than
from any other weather hazard related to tropical cyclones.
How are Hurricanes Named?
Since
1953, Atlantic tropical storms have been named from lists originated by
the National Hurricane Center and now maintained and updated by an
international committee of the World Meteorological Organization. The
lists featured only women’s names until 1979. After that, men’s and
women’s names were alternated. Six lists are used in rotation. Thus,
the 2001 lists will be used again in 2007.
The only time there is a change in the list is if a storm is so
deadly or costly that the continued use of the name would be
inappropriate for reasons of sensitivity. When this occurs, the name is
stricken from the list and another name is selected to replace it.
Sometimes names are changed. Lorenzo replaced Luis and Michelle replaced Marilyn.
