Storm surge a concern as Hurricane Ian batters Florida: Why is it so deadly?

A storm surge is an ‘abnormal rise of water generated by a storm’. As it gets closer to the coast, water gets pushed to the shore and piles up. Experts call it the most dangerous and destructive part of coastal flooding

FP Explainers September 29, 2022 15:08:49 IST
Storm surge a concern as Hurricane Ian batters Florida: Why is it so deadly?

A displaced boat sits beside the roadway in the southeast corner of Cape Coral on Wednesday night, Sept. 28, 2022, as the winds of Hurricane Ian continue to strike the flood-soaked streets. (Douglas R. Clifford/Tampa Bay Times via AP)

Hurricane Ian, one of the strongest hurricanes to ever hit the United States, has left Florida battered and bruised.

People have been trapped in their flooded home and millions left in the dark, after Ian, a Category 4 hurricane at landfall and the fifth-strongest when measured by wind speed to ever hit the US, slammed into southwest Florida.

The storm was about 90 kilometres southwest of Orlando with maximum sustained winds 120 kmph at 2 am. Thursday, the Miami-based hurricane center said.

Streets were turned into rivers and trees knocked down by Ian’s 241 kmph winds, pushing a wall of storm surge.

In Port Charlotte, along Florida’s Gulf Coast, the storm surge flooded a lower-level emergency room in a hospital even as fierce winds ripped away part of the roof from its intensive care unit, according to a doctor who works there.

The Federal Emergency Management Agency has warned that the storm surge is expected to cause “life-threatening storm surge and widespread flooding.”

But what is storm surge? Why is it so deadly?

Let’s take a closer look:

What is it?

The National Hurricane Centre (NHC) defines storm surge as “an abnormal rise of water generated by a storm.” As the storm gets closer to the coast, water gets pushed to the shore and “piles up” – hence creating a surge.

As per the website, if a storm surge coincides with high tide, it increases water levels even further.

Storm surge and rainfall both contribute to flooding during a hurricane, as per the NHC.

The NHC calls storm surge a ‘very complex phenomenon’ because it is sensitive to the slightest changes in:

  • Storm intensity
  • Forward speed
  • Size (radius of maximum winds-RMW)
  • Angle of approach to the coast
  • Central pressure (minimal contribution in comparison to the wind)
  • The shape and characteristics of coastal features such as bays and estuaries.

Why is it so deadly?

The FEMA website calls storm surge the ‘most dangerous and destructive part’ of coastal flooding.

“It can turn a peaceful waterfront into a rushing wall of water that floods homes, erodes beaches and damages roadways,” the website warns.

The NHC considers a storm surge of three feet life-threatening.

The NHC on Wednesday had increased Ian’s storm surge forecast to 12 to 18 feet, something never before seen in the region, as per CNN.

Though Ian dropped in strength by late Wednesday to Category 1 with 144 kmph winds as it moved overland, all isn’t clear yet.

Storm surges as high as 6.5 feet were expected on the opposite side of the state, in northeast Florida, on Thursday.

Storm surge a concern as Hurricane Ian batters Florida Why is it so deadly

A woman waits for state transportation after her home was destroyed by Hurricane Ian. AP

Hurricane Katrina, among the worst storms in US history, generated a storm surge of 25 to 28 feet above the normal tide level along parts of the Mississippi coast and 10 to 20 feet above normal tide along the southeastern Louisiana coast, as per the NHC.

The outlet quoted Ken Graham, the director of the National Weather Service as saying at a press briefing Wednesday, “We have to talk about the water.”

“Ninety percent of your fatalities in these tropical systems comes from the water,” he added, saying that figure includes deaths from storm surge and rainfall flooding.

“Water levels are quite high in those areas still and so it will take some time for the water to recede,” Cody Fritz, storm surge specialist at the National Hurricane Center, told CNN.

“There’s still plenty of onshore flow along the coast keeping water levels elevated, so while the peak surge values will decrease here relative to previous value, I still expect waters to be up for a while and the need to maintain the storm surge warnings,” Fritz added.

The NHC warned that its Storm Surge Risk Maps “make it clear that storm surge is not just a beachfront problem, with the risk of storm surge extending many miles inland from the immediate coastline in some areas.”

While a storm surge can’t be prevented citizens can minimise damage to their homes and keep loved ones safe by securing doors and windows, sealing cracks and gaps, and getting flood insurance.

With inputs from agencies

Read all the Latest NewsTrending NewsCricket NewsBollywood News,
India News and Entertainment News here. Follow us on FacebookTwitter and Instagram.

Updated Date:

also read

Madhya Pradesh teen suffers from ‘werewolf syndrome’: What is it? Is there a cure?
Explainers

Madhya Pradesh teen suffers from ‘werewolf syndrome’: What is it? Is there a cure?

Lalit Patidar, 17, from Nandleta village, said he was diagnosed with the condition at the age of six. Less than 50 cases of hypertrichosis have been recorded since it was first documented in 1648

Is Ukraine likely to win the war against Russia? What experts say
World

Is Ukraine likely to win the war against Russia? What experts say

Despite its successes, Ukraine has only reclaimed 55 per cent of the territory taken by Russia since the February invasion

Wait for US visa interview nears 1,000 days: Is it going to get better anytime soon?
Explainers

Wait for US visa interview nears 1,000 days: Is it going to get better anytime soon?

According to the US State Department, the current wait time for an interview for B1/B2 applicants (business and tourism) is at 999 days in Mumbai, 994 days in Hyderabad, 961 days in Delhi, 948 in Chennai, and 904 in Kolkata. It is important to note that these are estimates and not a guarantee of an