A Gulf of Mexico Current Could Throw This Hurricane Season for a Loop

A Gulf of Mexico Current Could Throw This Hurricane Season for a Loop
A satellite view of Hurricane Rita on September 22, 2005. Rita intensified over the Loop Current. (Image: NOAA, Getty Images)

The National Oceanic and Atmospheric Administration said this week that it’s likely we could once again be in for a very active hurricane season. As global warming supercharges ocean temperatures and the possibility of bigger, badder storms, a little-known current in the Gulf of Mexico may also be preparing to wreak some havoc.

The Loop Current is a current of water that flows into into the Gulf of Mexico, formed when warm water from the Caribbean crosses northward toward the mouth of the Gulf. “It’s like an elbow in a river,” said Brad Panovich, the chief meteorologist at WCNC Charlotte in North Carolina. “That little elbow goes up into the Gulf of Mexico, and it becomes a loop, like if you have a piece of string and there’s a loop in it.”

Unlike much of the rest of the Gulf, where a shallow layer of warmer water sits on top of much colder layers, the water in this current is warm and deep, going down hundreds of feet into the depths of the ocean — which can help it to supercharge storms.

“If one hurricane passes over shallow water, it can use up all the warm water at the surface,” said Panovich. “With the Loop Current, because it’s very deep, there’s plenty of fuel for that storm, and it doesn’t get deplenished like it does for other water.”

The movement of the current is random, dictated by a bunch of different factors like salinity and water temperature as well as basic fluid dynamics. But notably, the current is much higher up into the Gulf this year than usual. Some meteorologists have expressed alarm at how far north it is for this time of year. The Current’s current (sorry) position and behaviour mimics the way it was positioned in 2005, when seven major hurricanes developed in the Atlantic, and three particularly powerful ones — Katrina, Wilma, and Rita — developed after crossing over the Loop Current.

A Gulf of Mexico Current Could Throw This Hurricane Season for a Loop

“It’s the 363 kg gorilla in the Gulf,” University of Miami oceanography professor Nick Shay told the Verge.

Panovich warned against too much panic over the Loop Current specifically — but combined with other factors, he said, it’s part of what could be a concerning hurricane season.

“Of all the things that I’m worried about this season, [the Loop Current] would probably be 5 or 6 down the list,” Panovich said. “It’s kind of always been there, and in real time it’s more of a big deal than pre-season. Warm water is really important for hurricanes, obviously, but you still need a hurricane above it.”

One factor that’s causing Panovich alarm: the La Niña effect in play this season, which has the potential to create dry, warm conditions in the South, ideal for hurricanes to strengthen. In 2005, the world was between El Niño and La Niña years, meaning that the extra boosts for storms those effects can create were absent. Coupled with much-warmer overall temperatures in the Gulf, Panovich said, the whole situation is worrisome, regardless of the Loop Current. “There’s probably going to be more storms above that warm water than we had in 2005,” he said. “The seasonal set up this year on paper is far worse than it was in 2005.”

Amid all the hoopla over hurricane forecasts, it’s important for people to remember to take precautions.

“Be prepared, no matter what,” Panovich said. “We get caught up sometimes in the seasonal forecast. The number of storms, while important, increases your chances of being impacted, but it only takes one storm hitting your town to make a bad season.”