abc CH11: Steve Stewart
As Hurricane Florence moves closer to the coast, we've been hearing a lot about 'storm surge.'
Large death tolls have resulted from the rise of the ocean associated with many of the major hurricanes that have made landfall. Hurricane Katrina is a prime example of the damage and devastation that can be caused by surge. At least 1,500 people lost their lives during Katrina and many of those deaths occurred as a result of storm surge.
Storm surge is produced by water being pushed toward the shore by the force of the winds moving counter-clockwise around the storm. The maximum potential storm surge for a particular location depends on a number of different factors. Storm surge is a very complex phenomenon because it is sensitive to the slightest changes in storm intensity, forward speed, size, angle of approach to the coast, central pressure and the shape and characteristics of the coastline.
In addition to the power of surge, battering waves on top of the surge can cause significant destruction to structures. Water weighs around 1,700 pounds per cubic yard; extended pounding by waves can demolish any structure not specifically designed to withstand such forces. The two elements work together to increase the impact on land because the surge makes it possible for waves to extend inland.
(CNN)Hurricane Florence's wrath begins today.
The Carolina coasts can expect winds topping 80 mph late Thursday afternoon. And that's just the prelude to untold days of misery.
Don't be fooled by the fact that Florence has weakened slightly to a Category 2 hurricane; categories only denote the speed of sustained winds.
What makes this hurricane extremely dangerous are the deadly storm surges, mammoth coastal flooding and historic rainfall expected far inland.
"I don't care if this goes down to a Category 1," CNN meteorologist Chad Myers said. "We're still going to have a Category 4 storm surge."
TRACK THE STORM
Even worse: Florence is expected to hover over the Carolinas, whipping hurricane-force winds and dumping relentless rain at least through Saturday.
By the time it leaves, it's expected to have unloaded 10 trillion gallons of rainfall in North Carolina, weather.us meteorologist Ryan Maue said. That's enough to fill more than 15 million Olympic-size swimming pools.
• Fierce winds and rain have started: "Rain bands with tropical-storm-force winds (are) moving onshore on the outer banks of North Carolina," the National Hurricane Center said. Tropical-storm-force winds are between 39 and 73 mph.
• Florence is getting closer: As of 8 ET Thursday morning, the center of Florence was about 170 miles east-southeast of Wilmington, North Carolina, and about 220 miles east of Myrtle Beach, South Carolina.
• The path of the storm: Florence's center will approach the North and South Carolina coasts late Thursday and Friday, but it's unclear exactly when and where and it will make landfall. As the storm moves inland, Georgia, Virginia and Maryland will also be in peril.
• Storm surge is a huge threat: Strong winds will send rising water inland from the coastline of the Carolinas. The storm surge could rise up to 13 feet -- that's water inundating homes up to the first-floor ceiling, the National Hurricane Center said.
• Flight cancellations: At least 800 flights along the US East Coast have been canceled Thursday through Saturday ahead of the storm.
"Our sand dunes are healthy, but they're not going to be able to keep back a wall of water like that," he said. "Flooding is almost guaranteed."
Susan Faulkenberry Panousis has stayed in her Bald Head Island, North Carolina home during prior hurricanes, but not this time. She packed up what she could and took a ferry.
"When that last ferry pulls out ... it's unnerving to see it pull away and know, 'That's the last chance I have of getting off this island,'" she said Wednesday.
Emergencies declared in several states
Officials in several states have declared states of emergency, including in the Carolinas, Georgia, Virginia and Maryland, where coastal areas are still recovering from summer storms.
Florence's expanse even captured the attention of the astronauts and cosmonauts aboard the International Space Station, who have been tweeting pictures of the storm back to Earth.
"Watch out, America! #HurricaneFlorence is so enormous, we could only capture her with a super wide-angle lens from the @Space_Station, 400 km directly above the eye," German astronaut Alexander Gerst tweeted. "Get prepared on the East Coast, this is a no-kidding nightmare coming for you."
Florence is one of four named storms in the Atlantic. Tropical Storm Isaac is forecast to approach the Lesser Antilles Islands on Thursday. Hurricane Helene is veering toward Europe. And newly formed Subtropical Storm Joyce is not expected to threaten land soon.
Those four storms are brewing at the same time Hurricane Olivia is pounding Hawaii.
CNN's Kaylee Hartung, Jason Hanna and Steve Almasy contributed to this report.
While the 02568 National Hurricane Center projects storms during the 2006 hurricane season will mirror the intensity of Hurricane Katrina, one of the deadliest hurricanes in the history of the U.S., and one which caused more than $50 billion in damages to the Gulf Coast region, there are measures homeowners can take to better prepare their new-construction homes during the building phase.
The National Weather Service (NWS), the primary source of weather data, forecasts and warnings in the U.S.,02535 recommends homeowners verify that their homes meet current building code requirements for high winds, one of the many components associated with vicious Category 3+ hurricanes. The NWS says structures built to meet or exceed current building code high-wind provisions have a much better chance of surviving violent windstorms.
"Florida has some of the most stringent building codes in the U.S., led by 02562, Miami Dade County in South Florida," says Dr. Ronald Zollo, professor of civil and architectural engineering at the University of Miami and a licensed professional engineer. "Homeowners and builders need to move away from the traditional structures that cannot withstand the type of lateral forces that extreme weather, such as hurricanes, can place on a home."
Another concern for homeowners is flooding. Common with hurricanes, flooding can lead to extensive mold and structural damage. The National Oceanic and Atmospheric Association (NOAA) states that more than half of the nation's population lives and works within 50 miles of a coast, areas typically more prone to hurricane flooding.
Preparing For The Future 02537
Dr. Zollo encourages prospective new homeowners to think proactively. He urges those considering a new home purchase or a rebuild in coastal regions to talk with their builder or architects to understand local building codes and the effects of hurricane-force winds on their homes.
Dr. Zollo led a team from the University of Miami to survey damage from 1992's Hurricane Andrew in Florida. He believes that concrete materials, by virtue of their mass, rigidity and physical properties, are generally expected to outperform other construction materials when subjected to extreme environmental conditions, if constructed according to proper building codes.
A proven solution to reduce the structural damage from hurricanes is installing insulating concrete forms (ICFs)-hollow foam forms or panels that hold concrete in place.
"Homes built with ICFs using reinforced concrete provide homeowners with sustainable structures capable of withstanding extreme weather conditions," says Dr. Zollo. "They're easier to clean up after hurricane weather or flooding, and they provide the homeowner with moisture resistance in the walls themselves when combined with appropriate interior finishes. Those utilizing ICFs can also expect greater energy efficiency due to added thermal protection."
Owens Corning, a leader in building science technologies, produces the 02553, ICF option Fold-Form®. Solid concrete-reinforced walls built with Fold-Form® have been proven to provide superior protection against flying debris from winds as high as 200 miles per hour, when compared to conventional framed walls or hollow concrete block walls. By comparison, 02539 FEMA states that Hurricane Katrina achieved landfall wind speeds of 140 mph in southeast Louisiana.
According to Dr. Zollo, "In the future, I think we'll see faster recovery times for communities built with 02540, ICFs than those that are built without."
"While ICFs meet some of the U.S.'s most strict building codes and are up to nine times stronger than traditional wood frames, they're not just for hurricane protection," says Janet Albright, accessories manager, Residential & Commercial Insulation for Owens Corning. "We're seeing a dramatic increase in consumer demand throughout the entire U.S. for building products that are greener, offer greater energy efficiencies, air and moisture management and contribute to greater comfort levels by reducing noise in the home."