‘Brown water effect’ helped Ida stay at major hurricane status 8 hours after landfall
A special weather effect was allowing Ida to maintain its “major hurricane” status more than eight hours after making first landfall in Louisiana, the National Weather Service said.
Louisiana’s marshes, which sit inland and have been especially warm this August, have created a “brown ocean effect” that is helping the storm keep its strength as it slowly moves inland, weather service meteorologist Hannah Lisney said.
By 7 p.m. Saturday, the storm had only downgraded to a Category 3, meaning it sustained winds of less than 130 mph.
“The fact that it has held up as a major hurricane like eight hours after landfall is very uncommon,” Lisney said. “The Gulf is already very very warm, and then it moved over all of those marshes, and southern Louisiana isn’t a whole lot of land, it’s a lot of marsh.”
As the storm moved over the marshes, “it didn’t really help it die down much,” Lisney said.
One study on hurricanes and climate change said the “brown ocean effect” can happen when a strong tropical storm meets already extremely wet soil, which then releases a large amount of stored heat just as the ocean does, further fueling the storms power.
This isn’t the first time this effect has been seen. Meteorologists believe that Tropical Storm Bill, which hit southeast Texas in 2015, was fueled by the energy and heat emanating from the already wet ground in the region as if it were still over water.
This story was originally published August 29, 2021 at 8:48 PM.
