History teaches that a lack of hurricane awareness and preparation are
common threads among all major hurricane disasters. By knowing your
vulnerability and what actions you should take, you can reduce the
effects of a hurricane disaster.
You should be able to answer the following questions before a
hurricane threatens:
-
What are the Hurricane Hazards?
-
What does it mean to you?
-
What actions should you take to be prepared? Hurricane hazards come in
many forms:
high winds,
tornados,
flooding and
storm surge. This means it is important for your family to have a plan
that includes all of these hazards. Look carefully at the safety
actions associated with each type of hurricane hazard and prepare your
family disaster plan accordingly. But remember this is only a guide.
The first and most important thing anyone should do when facing a
hurricane threat is to use common sense.
The intensity of a landfalling hurricane is rated in terms of categories
that relate wind speeds and potential damage. The strongest winds usually
occur in the right side of the eye of the hurricane.
-
Tropical storm: Winds 39-73 mph; Wind damage unlikely;
Slow-moving storms can produce severe flooding.
-
Category 1 hurricane: Winds 74-95 mph; No real damage to
buildings; Damage to unanchored mobile homes; Some damage to poorly
constructed signs; Also, some coastal flooding and minor pier damage.
-
Category 2 hurricane: Winds 96-110 mph; Some damage to building
roofs, doors and windows; Considerable damage to mobile homes;
Flooding damages piers and small craft in unprotected moorings may
break their moorings; Some trees blown down.
-
Category 3 hurricane: Winds 111-130 mph; Some structural damage
to small residences and utility buildings; Large trees blown down;
Mobile homes and poorly built signs destroyed; Flooding near the coast
destroys smaller structures with larger structures damaged by floating
debris. Terrain may be flooded well inland.
-
Category 4 hurricane: Winds 131-155 mph; More extensive
curtainwall failures with some complete roof structure failure on
small residences; Major erosion of beach areas; Terrain may be flooded
well inland.
-
Category 5 Hurricane: Winds 156 mph and up; Complete roof
failure on many residences and industrial buildings; Some complete
building failures with small utility buildings blown over or away;
Flooding causes major damage to lower floors of all structures near
the shoreline; Massive evacuation of residential areas may be required.
-
Hurricanes can also produce tornados that add to the storm's
destructive power.
-
Studies have shown that more than half of the landfalling hurricanes
produce at least one tornado and some hurricanes produce several. In
1967, Hurricane Buelah spawned 141 tornadoes.
-
In general, tornados associated with hurricanes are less intense than
those that occur otherwise.
-
Tornado production can occur for days after landfall when the tropical
cyclone remnants maintain an identifiable low pressure circulation.
While storm surge is always a potential threat, more people have died from
inland flooding in the last 30 years. Most of those people drowned in, or
while attempting to abandon, their cars.
Inland flooding can be a major threat to communities hundreds of miles
from the coast as intense rain falls from these huge tropical air masses.
In June of 2001, Tropical Storm Allison produced extremely heavy rainfall
and catastrophic floods in the Houston area. Allison caused 41 deaths
across the U.S. and about $5 billion in damage, $4.8 billion in the
Houston area alone.
"The greatest potential for loss of life related to a hurricane is from
the storm surge." - Brian Jarvinen, National Hurricane Center
Storm surge is simply water that is pushed toward the shore by the force
of the winds swirling around the storm. This advancing surge combines
with the normal tides to create the hurricane storm tide, which can
increase the mean water level 15 feet or more.
In addition, wind driven waves are superimposed on the storm tide. This
rise in water level can cause severe flooding in coastal areas,
particularly when the storm tide coincides with the normal high tides.
Because much of the United States' densely populated Atlantic and Gulf
Coast coastlines lie less than 10 feet above mean sea level, the danger
from storm tides is tremendous.
