New Orleans and southern Louisiana have had more rain so far this year than they normally do on average.
This means the soil is saturated to the point that it essentially acts like the Gulf of Mexico, said CNN meteorologist Pedram Javaheri.
Moisture fuels the storm and the wet soils helped Ida to maintain hurricane strength for several hours after landfall, he said.
This is known as the “brown ocean effect,” a phenomenon that affects around 20% of tropical storm systems, explained Javaheri.
“Still maintaining hurricane strength really speaks volumes as far as how intense of a storm we’re dealing with,” he said.
“This is among the strongest storms you’ll ever see make landfall across the US.”