tropical double track friday
Two tropical systems in the Atlantic threaten Gulf coast
03:24 - Source: CNN
CNN  — 

Two tropical systems expected to reach the Gulf of Mexico by early next week could simultaneously become hurricanes in an unprecedented event.

Meteorologists say residents from Texas to Florida need to prepare for Tropical Storm Laura and Tropical Depression Fourteen, as they could impact the region in the coming days.

“We could be looking at two landfalls in a matter of just a day or two of each other at the beginning to middle part of next week, which is really unprecedented when you are talking about potentially two hurricanes in the Gulf of Mexico,” said CNN Meteorologist Jennifer Gray.

The storms haven’t yet entered the Gulf of Mexico but could intensify rapidly when they do. As of Friday evening, Grays says, there’s still a lot of uncertainty.

Forecasters say it’s hard to anticipate what the impact will be of having two systems in the Gulf of Mexico, but an unusual weather phenomenon known as the “Fujiwhara effect” could take place if the two systems are within roughly 900 miles of each other.

The Fujiwhara effect happens when two tropical systems come close together to influence each other’s movements and engage in dance around their common center, according to the National Weather Service.

Nothing is certain, but one of the outcomes could be that the two systems will then form a single massive storm, spin together as one, and then continue on their own paths, or “if one hurricane is a lot stronger than the other, the smaller one will orbit it and eventually come crashing into its vortex to be absorbed,” the NWS said.

Where are the storms now?

Tropical Storm Laura is about 40 miles east of Antigua and it’s moving west at 17 mph, the NWS said.

Monroe County in the Florida Keys on Friday declared a state of emergency. The county has ordered a mandatory evacuation for people who live on boats or in mobile homes, recreational vehicles, travel trailers and campers, according to a statement.

The northern coast of Haiti became the latest area on Friday afternoon to be put under a tropical storm warning.

Similar warnings have been issued for Puerto Rico, including Vieques and Culebra, U.S. Virgin Islands, British Virgin Islands, Saba and St. Eustatius, St. Maarten, St. Martin and St. Barthelemy, Antigua, Barbuda, St. Kitts, Nevis, Anguilla and the northern coast of the Dominican Republic from Cabo Cabron to the border with Haiti, the National Hurricane Center said.

“Heavy rainfall is likely across these areas beginning today and could cause mudslides and flash and urban flooding through Sunday,” the NHC said.

“Laura is expected to produce 3 to 6 inches of rain over Puerto Rico and the Virgin Islands, the Dominican Republic, the southern Haitian Peninsula and eastern Cuba through Sunday.”

Tropical storm watches are in effect for the southeastern Bahamas and the Turks and Caicos Islands, the NHC said.

The second system, Tropical Depression Fourteen (TD-14) was about 255 miles southeast of Cozumel, Mexico, on Friday afternoon. It was moving at about 13 mph toward the Yucatan Peninsula of Mexico, the NHC said.

A hurricane watch has been issued for Punta Herrero to Cancun, Mexico, and a tropical storm warning is in effect from north of Cancun to Dzilam, Mexico. Meanwhile, the government of Honduras discontinued a similar warning for the Bay Islands of Honduras.

The center of the system is expected to approach the east coast of the Yucatan Peninsula on Saturday before continuing to the Gulf of Mexico. TD-14 “could be near hurricane strength” late Saturday and gain more strength Sunday and Monday, the NHC said.

TD-14 is expected to become better organized Friday, meaning an upgrade to Tropical Storm Marco is likely to occur in the next 24 hours.

An extra focus on the Gulf of Mexico

Both systems are headed to the Gulf of Mexico.

“The longer-term forecast for [Tropical Storm Laura] looks to be complicated by the presence of another tropical system [TD 14] in the Gulf of Mexico next week,” said CNN meteorologist Brandon Miller. “Another tropical system spinning in the Gulf will make the forecast track less certain, as tropical storms and hurricanes in close range of each other can alter the winds in the atmosphere and influence each others’ tracks.”

So have we ever had two tropical storm strength systems simultaneously in the Gulf of Mexico before?

It has been 60 years since it has happened, said tropical researcher Phil Klotzbach. That occurred on June 18, 1959.

“On that date, we had an unnamed tropical storm (e.g., added after the season) and Beulah,” Klotzbach said.

Right now both storms are forecast to intensify to Category 1 hurricane strength as they move through the Gulf of Mexico.

“We have never had two hurricanes in the Gulf of Mexico simultaneously,” Klotzbach points out.

As of now, these systems are still several days away from impacting the US, so there is a lot that could change. However, since there are two systems at play here, essentially everything from Texas to Florida is an option.