Why a storm surge can be the deadliest part of a hurricane


In late August 2005, Hurricane Katrina was moving its way across the Gulf coast. It was classified as a Category 3 storm. Dangerous, but in a region with a long history
of Category 4 and 5 hurricanes, it wasn’t expected to be the most intense. Katrina was only one day away from the Louisiana
coast when the mayor of New Orleans issued an evacuation order. Unfortunately, it was too late. The sea level had already risen in a phenomenon
called storm surge. Water rapidly rose up against the city’s levees,
a series of walls designed to keep the area from flooding. Before Katrina made landfall, the levees broke. A wall of water rushed into the city, trapping
thousands. What followed was one of the worst natural disasters in US history. “We’re expecting storm surge of 20 to 30 feet high” “Flood waters are drenching city streets “A levee broke during the height of the storm” “There are bodies…uh… floating in the water there.” Storm surge was the main cause of death during
Hurricane Katrina. In fact it can be the most dangerous part
of any hurricane. It occurs when strong winds from an approaching
hurricane push water into the shore. As the sea rises, a bulge of water sweeps
over coastal areas, causing destruction along the way. These are the normal astronomical tides at
Dauphin Island to the east of New Orleans. When you compare them to the water levels
during hurricane Katrina — you can see the dramatic rise. That’s the storm surge. What makes this rise dangerous is that it
starts to build up before the hurricane makes landfall So the coastal flooding from it can make evacuation
procedures and the impact of a hurricane much worse. In 2008, hurricane Ike caused a big storm
surge around Galveston, TX a day before landfall. The rising water cut off evacuation routes
stranding hundreds. More recently, the National Hurricane Center
issued dire warnings for the storm surge accompanying Hurricane Irma, the most powerful storm to ever rage through the Atlantic Ocean. A storm surge can also be unpredictable. Rising sea levels caused by global warming
increase the risk of storm surge. But there are many factors that can change
its size and strength. For example, the largest one recorded before
Katrina was about 22 feet, during Hurricane Camille in 1969. But Camille was a category 5 storm with 190
mph winds. Katrina was only a category 3 with 130 mph
winds, but it had a storm surge of about 28 Katrina had slower winds than Camille but
it was twice as wide, which dramatically increased the storm surge. These calculations help forecasters warn communities
at risk. But they’re often not enough to prevent
damage on the ground. This map shows the highest storm surge events
worldwide since 1880. In the US, the eastern and southeastern coastlines
are among the most vulnerable areas for storm surges in the world. Along the east coast, hurricane Sandy got
its strength from a massive storm surge in 2012. On the Gulf Coast side, places like Texas
and South Florida have seen multiple hurricanes so they’ve built infrastructure to help defend
against excessive flooding. Levees and seawalls are designed to stop or
redirect rising water away from cities. But even those can be inadequate, as seen
during hurricanes Katrina and more recently, Harvey. What really concerns experts, though, are
places that don’t experience a lot of hurricanes but are still vulnerable to storm surge. This map shows that in the event of a big
hurricane, based on the characteristics of the shoreline, the coasts of Northwest Florida
and Georgia would be at comparable risk to the Gulf Coast. These areas have shallow water, which means
sea level can rise faster and water can reach further inland making the flooding worse. But they’ve seen fewer hurricanes than the
Gulf Coast and they are likely to be less prepared. So when a major hurricane like Irma hits low-lying
areas like these, the storm surge can be the first and deadliest thing headed their way.

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Comments

  1. When i watched this. I cleaned the 4 corners of my led tv. I though it was broken. But it was just the style of the video with dark corners 😑.

  2. Oh Allah help us survive this monster Hurricane and protect the properties and citizens from harm. Stay strong and vegelent fellow Carolinas and Virgina. We will continue praying for you.

  3. This is BS A storm surge is a rapidly rising tide, not a wall of water, like a tsunami. New Orleans is unique, in that the city is below the level of the river, depending on huge pumps to remove overflowing water. A corrupt government that squandered the money earmarked for levee maintenance was one of the big problems in New Orleans. Is your city lower than the nearby river or ocean? Do you have deteriorated flood control levees?

  4. All the best Florence. No sympathy for most of the inbred retards in these southern states who think climate change is a chinese hoax. Well let's see you slap a tariff on these floods LOL!

  5. Hmph. In hong kong we got a super typhoon waiting for us. It definitely will do more damage than the one last year in hong kong. Also, pray for macau so they wont suffer as much as last year

  6. I'm surprised to find that there's not a single mention of Donald Trump on this video. I was expecting VOX blamming Donald Trump for the water surge that'll happens because DT fund cutting.

  7. I live on on the west coast so I have not experienced a hurricanes, but geological disasters could happen here, there faults like the San Andreas and Juan de fuca faults. Also, there are the Many volcanoes in the Cascade Mountains and many of them have not erupted in long time, some of them could be worse than the Mt. Saint Helens eruption

  8. Hurricane, cyclone, earthquake, volcanic eruption, heavy rain all of these phenomen are normal but it the presence of humans there that make it look bad

  9. Hope people realize it's not the wind that kills but the storm surge and flooding that do. Don't think it's because it's a Cat 1 or 2 hurricane that you are safe. Better be safe than sorry by evacuating when it is mandatory. Physical things can be replaced but not lives. This is coming from a survivor of Hurricane Harvey, which was a Cat 1 when it hit Corpus Christi, and but was only a Tropical Storm when it turns around and hit Houston.

  10. I've got one question:
    What happens to the islands that such storms cross before reaching US-mainland like haiti, dominican rep. Cuba and the bahamas and why aren't they mentioned most of the time.

  11. i'd like to point out that hurricane florence isnt the only typhoon/ hurricane (whatever u call it) happening right now.
    typhoon mangkhut or ompong (category 5) hit hong kong harder than it should've have, firstly, it hit the Philippines first and then weakened, and then slammed hong kong.
    id like people to notice typhoon mangkhut because for 1
    -its almost as strong as typhoon haiyan
    -category 5

  12. 1:38 I don't understand why people would even live on a small island like that Knowing full well hurricanes can happen over there! I looked on google street view, they hardly have any protection against high waters! Maybe at most 1,5 meters high! That is not enough! When will they learn???

  13. It's true that the storm surge can come ashore before the bulk of a hurricane, but the very highest water levels usually occur around the eye. So right when the wind is strongest, is when your house near the coast is being smashed to pieces by the ocean. This makes it less likely that you can survive.

  14. Yeah, if no one wants to ditch meat and other animal products; still uses cars all the time; often uses airplanes to travel; heat their flat with oil; consume a lot and so on, climate change will happen faster and stronger – and so will storm surges and hurricanes!

    Do you wanna be part of the problem or the solution?

  15. Your map at 2:43 misses at least all storm surge events at in the North Sea. There been many and the highest ones almost reached 20 feet.

  16. Note that while Katrina was a high end Cat 3 at landfall, it was a firm Cat 5 at peak intensity in the middle of the Gulf.

  17. you guys near the hurricane please be safe!!!!!!! I hope everyone stays vigilant and smart. I will try and make a YouTube video about dorian

  18. an underground group has a weather space station and has used it to make weather worse and may have caused all the drain systems to fail during the next big storm

  19. Storm surge from Dorian has decimated northern Bahamas. People, or me, growing up, you learn so much about the wind of a hurricane. Board up, tie down, batten down. But the WATER is what I've seen cause the most damage. The money and energy spent on wood and rope really could go toward rafts/tubes for the family.

  20. This video is factually incorrect. They claim the levees broke before the storm hit which is not accurate. They also imply the levees broke and that's why more people didn't evacuate, also not true.

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