Hurricane Ida is expected to make landfall Sunday, threatening to bring dangerous wind, storm surge and rain to the Gulf Coast exactly 16 years after the arrival of Hurricane Katrina, one of the most costly natural disasters in American history, which left more than 1,800 dead and produced more than $100 billion in damages.
The overall impact of storm surge from Ida is predicted to be less severe than during Katrina. Because that storm began as a Category 5 hurricane in the Gulf of Mexico before weakening as it approached landfall, it generated enormous storm surge, which brought over 20 feet of water to parts of the Mississippi coast. Current projections put the storm surge of Ida at 10 to 15 feet.
“Fifteen-foot sure can do a lot of damage,” said Barry Keim, a professor at Louisiana State University and Louisiana State Climatologist. “But it’s going to be nothing in comparison with Katrina’s surge.”
Improvements to the levee system following Katrina have better prepared the New Orleans metro area for the storm surge.
However, the areas likely to receive the most severe surge from Ida may be less equipped to handle it than the area hit by Katrina, said Dr. Keim.
Ida is expected to make landfall to the west of where Katrina struck, bringing the most severe storm surge impacts to the Louisiana coast west of the Mississippi River rather than east of the river along coastal Mississippi, as Katrina did.
“We are testing a different part of the flood protection in and around southeast Louisiana than we did in Katrina,” said Dr. Keim. “Some of the weak links in this area maybe haven’t been quite as exposed.”
While the impacts of Ida’s storm surge are expected to be less severe than Katrina’s, Ida’s winds and rain are predicted to exceed those that pummeled the Gulf Coast in 2005.
Ida is expected to make landfall on the Gulf Coast as a Category 4 storm with peak winds of 130 mph, while Katrina made landfall as a Category 3 with peak winds of 125 mph.
“It could be quite devastating — especially some of those high rise buildings are just not rated to sustain that wind load,” said Jamie Rhome, acting deputy director of the National Hurricane Center.
The severe damage from Hurricane Laura, which struck southwest Louisiana last year as a Category 4 storm, was caused primarily by high winds peaking at 150 mph. The storm caused 42 deaths and damage costing more than $19 billion.
Ida’s rainfall also threatens to exceed Katrina’s highs.
The National Hurricane Center estimates that Ida will drench the Gulf Coast with 8 to 16 inches of rain and perhaps as much as 20 inches in some places. Katrina brought 5-10 inches of rain with more than 12 inches in the most impacted areas.
“That is a lot of rainfall,” said Mr. Rhome. “Absolutely the flash flood potential in this case is high, very high.” Especially combined with storm surge, he said, such intense levels of rainfall could have a “huge and devastating impact to those local communities.”