intensity of a landfalling hurricane is expressed in terms of categories that
relate wind speeds and potential damage. According to the Saffir-Simpson Hurricane Scale, a
Category 1 hurricane has lighter winds compared to storms in higher categories.
A Category 4 hurricane would have winds between 131 and 155 mph and,
on the average, would usually be expected to cause 100 times the damage of
the Category 1 storm. Depending on circumstances, less intense storms may
still be strong enough to produce damage, particularly in areas that have not
prepared in advance.
storm-force winds are strong enough to be dangerous to those caught in them.
For this reason, emergency managers plan on having their evacuations complete
and their personnel sheltered before the onset of tropical storm-force winds,
not hurricane-force winds.
winds can easily destroy poorly constructed buildings and mobile homes. Debris
such as signs, roofing material, and small items left outside become flying
missiles in hurricanes. Extensive damage to trees, towers, water and underground
utility lines (from uprooted trees), and fallen poles cause considerable disruption.
Windows falling from a high-rise building
King Headquarters' CEO office
in Miami after Hurricane Andrew
Hurricane Frederic (1979)
buildings are also vulnerable to hurricane-force winds, particularly at the
higher levels since wind speed tends to increase with height. Recent research
suggests you should stay below the tenth floor, but still above any floors at
risk for flooding. It is not uncommon for high-rise buildings to suffer a great
deal of damage due to windows being blown out. Consequently, the areas around
these buildings can be very dangerous.
strongest winds usually occur in the right side of the eyewall of the hurricane.
Wind speed usually decreases significantly
within 12 hours after landfall. Nonetheless, winds can stay above hurricane
strength well inland. Hurricane Hugo (1989), for example, battered Charlotte,
North Carolina (which is 175 miles inland) with gusts to nearly 100 mph.
The Inland High Wind Model can be used by emergency managers to estimate
how far inland strong winds extend. The inland
wind estimates can only be made shortly before landfall when the windfield
forecast errors are relatively small. This information is most useful in the
decision-making process to decide which people might be most vulnerable to high
winds at inland locations.
TO ASK YOUR COMMUNITY LEADERS
Does your community building code set standards that will help buildings withstand
winds in a major hurricane?
your shelter facilities include long-span roofs or unreinforced masonry walls
(such as gymnasiums) that are vulnerable in high winds?
WIND SAFETY ACTIONS
HIGH WIND EVENTS
THE WIND (0.2mb)
MAYFIELD DISCUSSES - HURRICANE
INTENSIFICATION (0.2mb MP3)
FOR BUSINESS & HOME SAFETY (IBHS)
HIGH WIND SAFETY
ACTIONS - before hurricane season
out if your home meets current building code requirements for high-winds.
Experts agree that structures built to meet or exceed current building code
high-wind provisions have a much better chance of surviving violent windstorms.
Please visit IBHS (Institute for Business and Home Safety)
all windows by installing commercial shutters or preparing 5/8 inch plywood
panels. More info
doors are frequently the first feature in a home to fail. Reinforce all garage
doors so that they are able to withstand high winds. More
you do not live in an evacuation zone or a mobile home, designate an interior
room with no windows or external doors as a Safe Room. More
info #1 More info #2
hurricane season, assess your property to ensure that landscaping and trees
do not become a wind hazard.
- Trim dead wood and weak / overhanging branches from all trees.
- Certain trees and bushes are vulnerable to high winds and any dead tree
near a home is a hazard.
- Consider landscaping materials other than gravel/rock.
HIGH WIND SAFETY
ACTIONS - as a hurricane approaches
mobile / manufactured homes are not built to withstand hurricane force winds. Residents
of homes not meeting that level of safety should relocate to a nearby safer structure once local officials issue a hurricane
evacuation order for their community.
a hurricane warning is issued, install your window shutters or plywood panels.
a hurricane warning is issued for your community, secure or bring inside all
lawn furniture and other outside objects that could become a projectile in
carefully for safety instructions from local officials, and go to your designated
Safe Room when directed to do so.
- Monitor NOAA
not leave your Safe Room until directed to do so by local officials,
even if it appears that the winds calmed. Remember that there is little to
no wind in the eye of a hurricane.
HIGH WIND EVENTS
Andrew was a small but vicious Category 5 hurricane that hit south Florida
followed by landfall in Louisiana as a Category 3 hurricane. Estimated sustained
winds of 145 mph with gusts in excess of 175 mph devastated portions of central
and southern Dade county. Twenty-three people died in the U.S. due to Andrew,
and the estimated property damage of $25 billion makes it the costliest hurricane
in U.S. history. More ...
Devastated the West Indies and the Southeastern United States, including South
Carolina cities Charleston and Myrtle Beach. Hugo was responsible for sixty
deaths and $7 billion in damages, with a storm surge estimated at 19.8 feet
at Romain Retreat, South Carolina.
Alicia made landfall as a Category 3 hurricane near Galveston Island,
Texas. The storm had wind gusts up to 127mph and spawned 23 tornadoes near
Houston and Tyler, TX. Broken glass littered the streets of downtown Houston
as many windows were broken by flying debris.
A Category 5 hurricane, the most powerful on the Saffir/Simpson Scale with
maximum winds of more than 200mph devastated the Mississippi coast. The final
death count for the U.S. is listed at 256. This includes 143 on the Gulf coast
and another 113 from the Virginia floods.
Hurricane Hazel was an accelerating Category 4 hurricane that made landfall
near Myrtle Beach, SC on 15 October and roared northward through the eastern
United States. Strong winds spread well inland, with Washington, D.C., measuring
sustained hurricane-force winds and Philadelphia measuring gusts of 100 mph.
Ninety-five people died due to Hazel.
fast moving category 3 hurricane that made landfall in Long Island and New
England on August 31. Sustained winds of 80 to 100 mph were reported over
much of eastern Connecticut, all of Rhode Island, and eastern Massachusetts.
A peak gust of 135 mph was measured at Block Island, while gusts of 100
to 125 mph occurred over much of the affected area. Sixty people died due
to Carol. More