Freak ‘Wake Low’ Storm Capsizes Vessel, Stirs Up Hurricane-Force Winds

Freak ‘Wake Low’ Storm Capsizes Vessel, Stirs Up Hurricane-Force Winds
Photo: Associated Press, AP

At least a dozen people are still missing off the coast of Louisiana after a commercial boat capsized in rough weather on Tuesday afternoon. Authorities have rescued six of the at least 18 passengers aboard the Seacor Power, a 39.3-metre workboat for the oil industry, after it capsized in the Gulf of Mexico off the coast of Port Fouchon, a big fossil fuel hub in the state.

The Coast Guard has been leading the rescue effort, but multiple private boats, known as Good Samaritan vessels, have also pitched in to help. Some non-Coast Guard boats that arrived first on the scene rescued four of the six people saved thus far. The Coast Guard said it is still confirming how many people were aboard the boat when it capsized.

The Seacor Power is what’s known as a lift vessel, which transports workers and helps with operations at offshore rigs and other sites. The Times-Picayune reported that the boat can carry more than 151,416 litres of fuel oil; officials have not reported if any of this oil has been spilled in the accident.

The weather has been pretty wild in Louisiana for the past few days. The National Weather Service issued a flood warning for the entire southeastern region of the state for Tuesday through Thursday, warning of rainfall totals between 8 to 12 cm and winds up to 72.4 kph. The agency also issued a special marine warning on Tuesday for the waters where the boat capsized. The wind reached 121 kph closer to the coast during the storm. Meanwhile, an oil rig farther offshore measured a gust of 180 kph, and another ship reportedly in the Port Fourchon area recorded a gust at 188 kph. That’s the equivalent of a Category 3 hurricane.

The source of the gnarly weather is what’s known in as a “wake low.” These types of systems can form behind a squall line of storms. After the squall moves through an area, a pocket of warm air can sometimes form in their wake through a series of meteorological processes (hence the “wake” part). The temperature difference between that warm air and surrounding cooler air can lead to powerful blasts of wind as the atmosphere tries to balance these opposing air masses. They’re fairly rare, though not unheard of; a powerful one blasted Nashville just last year. But they can be hard to forecast.

Coast Guard spokesman Petty Officer Jonathan Lally told local news that there were “multiple vessels hit” off the coast in the same burst of bad weather that impacted the Seacor Power.

“We expected some winds and possible rains, but nothing as extensive as what took place on the coastal areas of Jefferson Parish,” local Councilman Ricky Templet told the Times-Picayune.

Louisianans took to social media to share footage of the wild weather. A video posted to Twitter of the storm from a resident of Grand Isle, 13 km north of where the boat capsized, shows sheets of wind and a docked boat rocking wildly. Bruce Simon, a resident of Cut Off, a town north of Port Fouchon, wrote in a Facebook post that he saw boats flip and taking on water in 3- to 6-metre waves. Other social media photos appear to confirm coastal flooding and capsized boats.

“Ive NEVER Heard soo many MAYDAY calls in my life!” Simon wrote.

The region isn’t out of the woods yet. More storms are on the way for the rest of the week, and reports of dime-sized hail are already coming in on Wednesday morning across Louisiana and the NWS has issued flash flood warnings and small craft advisories from Texas to Alabama. The NWS Mobile office also warned another wake low isn’t out of the question for Wednesday afternoon.