Tropical Storm Laura and Tropical Storm Marco organize quickly and begin to gain strength after days of struggle to survive. Both systems are forecast to make new week landfall along the Gulf Coast, one day apart and miles apart.
Two hurricanes in the Gulf of Mexico at once – if it occurs – would be a first on record.
Louisiana and Mississippi officials have both declared a state of emergency.
Tropical Storm Marco
On Saturday, hurricane fighters exploring Tropical Storm Marco in the western Caribbean found a very robust system, with intense thunderstorms blowing near the center and stronger winds blowing in circulation. By late morning, the storm was near the western tip of Cuba. Winds were 65 mph and the system moved north-northwest around 12 mph in the Gulf of Mexico.
Hot water will allow a window of intensification, and Marco is expected to become a hurricane this weekend as it heads northwest Texas. However, top-level wind shear is forecast for the system to weaken the system before landfall on Tuesday, likely along the Texas coast.
National Hurricane Center
Tropical Storm Laura
Tropical Storm Laura is also experiencing a large increase in thunderstorms, but that has yet to translate into a rise in wind. As of 11 a.m., the National Hurricane Center said the storm was located just southwest of Puerto Rico, with winds of 40 mph. It is moving west at 18 mph. Given the mass thunderstorms that are developing, winds are likely to increase later on Saturday.
The storm is predicted to move near or over Hispaniola and Cuba, which will disrupt circulation somewhat, likely banning it from gaining too much power in the short term. But once the system reaches the Gulf of Mexico on Monday, light environmental winds and above-normal water temperatures are likely to burn intensification.
Starting Saturday, the storm is predicted to become a hurricane next week before making landfall Wednesday, possibly in Louisiana, or even Texas. That means Marco and Laura might make landfall within hundreds of miles of each other, just 24 hours apart.
National Hurricane Center
Despite the systems being so close together, they can not combine to become a “supercane”. This is because each system has sinking air at its edge, which presses on the other system. So, when two systems are so close, the larger one tends to weaken the smaller one. And in some cases, they can even dance around each other in a phenomenon called the Fujiwhara effect.
2020 Atlantic hurricane season
The 2020 season is far ahead of record pace, with Marco as the first 14th named storm on record in the Atlantic. The previous record for the 14th storm is September 2, set back in 2005 and 2011.
The record pace is due in part to abnormally warm sea surface temperatures over most of the Atlantic Ocean, which has been near record levels most of the summer. Since 1900, tropical Atlantic waters have been warned about 2 degrees Fahrenheit due to human-caused climate change.
The image below shows departure from sea surface temperature from normal now. Expanded areas in orange – almost the entire basin – show above normal temperatures, and very small patches in blue indicate below normal temperatures.
CBS News
It is warmer than normal water as high octane fuel for tropical systems. Therefore, both Marco and especially Laura need to be closely monitored for rapid intensification, which could quickly turn a mid-storm into a disaster, as it did with Hurricane Michael in 2018.
Rapid intensification is becoming more frequent in a warmer world. 2018 research calculated that since the 1980s, rapid intensification has increased by 4.4 mph per decade.
.
