FacebookTwitterGoogle+RedditEmail

Is the National Hurricane Center Underestimating Irma’s Storm Surge?

In 2015, ten full years after Hurricane Katrina, the National Hurricane Center (NHC) finallybegan making projections in advance regarding potential storm surge. This even though “[s]torm surge is often the greatest threat to life and property from a hurricane,” according to NHC [pdf]. In fact, the “fatalities that we saw in Sandy [117] and in Katrina [1,800+] were mostly, not exclusively but mostly, seawater from storm surge.” Currently, NHC is projecting that many areas along the coast in southern Florida, including in and around Miami, have a 10% or greater chance of a strong storm surge. The worst areas, particularly just north of the Everglades and in Homestead, have a chance to hit the top category (red) of 9+ feet. But is 9+ feet a reasonable high end category?

Hurricane Andrew (1992) saw storm surges in southern Florida of about 4-7 feet in the worst places with one recording (at Burger King Headquarters) of nearly 17 feet, but the worst projections of a massive, deadly surge did not materialize.

In this article Jeffrey Masters, co-founder of The Weather Underground and a former“Hurricane Hunter” with NOAA, helpfully discusses the key factors that determine the magnitude of a particular storm surge during a hurricane. The critical factor is size of the hurricane, rather than the two more well-known factors of wind speed and barometric pressure. Masters compares Hurricane Katrina (a category 3 hurricane upon land fall) and the much stronger Hurricane Camille (category 5, also a land fall in Louisiana, 1969). Even though two categories less intense on the Saffir-Simpson Scale, “Katrina’s radius of maximum winds was about 30 miles, double Camille’s,” and “Katrina set in motion a volume of water about four times greater than Camille did.”

So how does Hurricane Irma compare to Hurricane Andrew in terms of size? Quite frighteningly so, actually. While other factors (such as high tide or low tide at land fall, where direct land fall actually occurs, and the level of barometric pressure when it hits) will contribute to the storm surge levels, it is the massive difference between Andrew (left in this graphic) versus Irma (right) that is giving me a terrible feeling in the pit of my stomach. (I had been scheduled to officiate a wedding in Miami this Saturday.)
Officials in Florida have used the storm surge projections to determine where to suggest or mandate evacuation. If the surge is like Sandy’s (10-12 feet in the worst spots), the NHC projections of 9+ feet at the upper end of the scale may seem quite justified. If, however, the monster size of Irma means a surge more like Katrina’s, nearly 28 feet at it’s highest as discussed by Masters, we may be looking a scale of devastation and loss of life that will raise very serious questions about whether adequate and accurate information was provided in advance to decision makers in Florida.

As of Tuesday, according to Masters, Irma’s radius of maximum winds was 35 miles across, five miles wider than Katrina’s, and growing. This could very well mean a storm surge of 15-20 feet or more for Florida, potentially more than double the 9 feet that begins NHC’s highest category.

At this point, we may only be able to hope and pray for the best. However, if you are reading this in southern Florida ahead of Irma’s land fall and can still make a choice to evacuate, it is highly advisable.

More articles by:

Doug Johnson Hatlem is best known for his work as a street pastor and advocate with Toronto’s homeless population from 2005-2013. He is now a film producer and free-lance writer based in Chicago.

November 13, 2018
Patrick Cockburn
The Midterm Results are Challenging Racism in America in Unexpected Ways
Victor Grossman
Germany on a Political Seesaw
Cillian Doyle
Fictitious Assets, Hidden Losses and the Collapse of MDM Bank
Lauren Smith
Amnesia and Impunity Reign: Wall Street Celebrates Halliburton’s 100th Anniversary
Joe Emersberger
Moreno’s Neoliberal Restoration Proceeds in Ecuador
Carol Dansereau
Climate and the Infernal Blue Wave: Straight Talk About Saving Humanity
Dave Lindorff
Hey Right Wingers! Signatures Change over Time
Dan Corjescu
Poetry and Barbarism: Adorno’s Challenge
Patrick Bond
Mining Conflicts Multiply, as Critics of ‘Extractivism’ Gather in Johannesburg
Ed Meek
The Kavanaugh Hearings: Text and Subtext
Binoy Kampmark
Concepts of Nonsense: Australian Soft Power
November 12, 2018
Kerron Ó Luain
Poppy Fascism and the English Education System
Conn Hallinan
Nuclear Treaties: Unwrapping Armageddon
Robert Hunziker
Tropical Trump Declares War on Amazonia
John W. Whitehead
Badge of Shame: the Government’s War on Military Veterans
Will Griffin
Military “Service” Serves the Ruling Class
John Eskow
Harold Pinter’s America: Hard Truths and Easy Targets
Rob Okun
Activists Looking Beyond Midterm Elections
Binoy Kampmark
Mid-Term Divisions: The Trump Take
Dean Baker
Short-Term Health Insurance Plans Destroy Insurance Pools
George Wuerthner
Saving the Buffalohorn/Porcupine: the Lamar Valley of the Gallatin Range
Patrick Howlett-Martin
A Note on the Paris Peace Forum
Joseph G. Ramsey
Does America Have a “Gun Problem”…Or a White Supremacy Capitalist Empire Problem?
Weekend Edition
November 09, 2018
Friday - Sunday
Louis Proyect
Why Democrats Are So Okay With Losing
Andrew Levine
What Now?
Jeffrey St. Clair
Roaming Charges: Chuck and Nancy’s House of Cards
Brian Cloughley
The Malevolent Hypocrisy of Selective Sanctions
Marc Levy
Welcome, Class of ‘70
David Archuleta Jr.
Facebook Allows Governments to Decide What to Censor
Evaggelos Vallianatos
The Zika Scare: a Political and Commercial Maneuver of the Chemical Poisons Industry
Nick Pemberton
When It Comes To Stone Throwing, Democrats Live In A Glass House
Ron Jacobs
Impeach!
Lawrence Davidson
A Tale of Two Massacres
José Tirado
A World Off Balance
Jonah Raskin
Something Has Gone Very Wrong: An Interview With Ecuadoran Author Gabriela Alemán
J.P. Linstroth
Myths on Race and Invasion of the ‘Caravan Horde’
Dean Baker
Good News, the Stock Market is Plunging: Thoughts on Wealth
David Rosen
It’s Time to Decriminalize Sex Work
Dan Glazebrook
US Calls for a Yemen Ceasefire is a Cynical Piece of Political Theatre
Jérôme Duval
Forced Marriage Between Argentina and the IMF Turns into a Fiasco
Jill Richardson
Getting Past Gingrich
Dave Lindorff
Not a Blue Wave, But Perhaps a Foreshock
Martha Rosenberg
Dangerous, Expensive Drugs Aggressively Pushed? You Have These Medical Conflicts of Interest to Thank
Will Solomon
Not Much of a Wave
Nicolas J S Davies
Why Yemeni War Deaths are Five Times Higher Than You’ve Been Led to Believe
FacebookTwitterGoogle+RedditEmail