SUFFOLK CLOSEUP - Thinking About A Hurricane On LI Think Storm Surge

SUFFOLK CLOSEUP

By Karl Grossman

We all worried last month looking at TV and the westward track of Hurricane Florence about the consequences if it hooked to the north and struck in the upper portion of the Atlantic Coast.  That possibility was suggested by some forecasters, but Florence’s track was unswervingly westward—hitting North Carolina head-on.

And Florence was a Category 1 hurricane when it hit the Carolinas—after days of being at Category 4—and still was a “monumental disaster” for North Carolina, as its Governor Roy Cooper put it. What was routinely referred to as a “monster storm” did equivalent damage in South Carolina.

What would be the consequences if a Category 4 hurricane—a level that’s become far, far more frequent these days due to climate change producing warmer water for hurricanes to feed on—smashed into Long Island?

With an analysis of Long Island hurricane impacts is Professor Scott A. Mandia of Suffolk County Community College. He is a meteorologist—with a master’s degree in meteorology from Pennsylvania State University—who teaches courses at Suffolk Community in weather and climate change. He is assistant chair of the college’s Department of Physical Sciences. 

It is not pretty. Indeed, it is downright scary. Click on to see Professor Mandia’s analysis at http://www2.sunysuffolk.edu/mandias/38hurricane/storm_surge_maps.html 

His analysis states that it would only require a Category 1 storm for Montauk Point to be “completely cut off from the rest of the South Fork.” If there were a Category 3 hurricane, “Much of the North and South Forks are entirely under water.”

A Category 4 hurricane “inundates”—a term widely used by meteorologists these days to describe severe flooding—“entire” areas of Long Island, says Professor Mandia in his analysis. This would include on the East End: North Haven, Greenport, Montauk, Westhampton Beach and Orient. It also “inundates” Shelter Island “except for a few high points,” along with Plum Island and Gardiner’s Island.

A Category 4 hurricane “inundates” in western Suffolk County the “entire” communities of Amityville, Lindenhurst, Babylon, West Islip and Bay Shore, among other areas.

A Category 4 hurricane “inundates” in Nassau County the “entire” communities of Woodmere, Valley Stream, Lynbrook, Long Beach, Atlantic Beach, Lido Beach, Freeport, Merrick and Wantagh, among other areas.    

Professor Mandia’s analysis is part of a series of web pages he presents. They are headed “The Long Island Express, The Great Hurricane of 1938, Long Island Hurricane Climatology.” He is an expert on the Hurricane of 1938 which ravaged Long Island and much of New England exactly 80 years ago last month. The Saffir-Simpson Hurricane Wind Scale, which sets the categories wasn’t in use then, but today the Hurricane of 1938 is considered to have been a Category 3 hurricane when it struck Long Island. 

A Category 4 hurricane is one with a wind speed of 131 to 155 miles per hour; Category 3—111 to 130; Category 2—96 to 110; Category 1—74 to 95.  

Professor Mandia does not make projections for the top category of hurricanes on the Saffir-Simpson Wind Scale, Category 5 with winds of 156 miles per hour and stronger, because there is no evidence that a Hurricane 5 hurricane has struck Long Island. But, he said in an interview, “I wouldn’t be surprised that with warmer water here that at some point this century a Category 5 hurricane will hit Long Island.”

Here, as in the Carolinas, the key issue regarding loss of life and much of damage would not be wind speed but storm surge. Storm surge is defined by the National Oceanic and Atmospheric Administration as “the abnormal rise in seawater level during a storm, measured as the height of the water above the normal predicted astronomical tide. The surge is caused primarily by a storm’s winds pushing water onshore.”

It would be, in the case of a Category 4 hurricane, well over 20 feet, as high as 28 and 29 feet, in some areas of Suffolk and Nassau Counties. Click on the map of Long island on Professor Mandia’s analysis and you’ll find the estimated storm surge for where you live.

Professor Mandia says: “Hurricane storm surge causes approximately 90% of all storm deaths and injuries and much of the damage, therefore it is important to residents of Long Island…to be aware of the areas that will be affected by the storm surge. The southern shore of Long Island is most vulnerable to storm surge inundations because hurricane landfall will first occur there and the low elevation will allow sea water to move well inland.”

More next week.

Karl Grossman is a veteran investigative reporter and columnist, the winner of numerous awards for his work and a member of the L.I. Journalism Hall of Fame. He is a professor of journalism at SUNY/College at Old Westbury and the author of six books.