Tropical Storm Marco was swirling over the Gulf of Mexico early on Sunday, heading for a possible hit on the Louisiana coast as a hurricane, while Tropical Storm Laura knocked utilities out as it battered Hispaniola, following a track forecast to take it to the same part of the US coast – also as a hurricane.
It would be the first time two hurricanes have appeared in the Gulf of Mexico simultaneously, according to records dating to at least 1900, said Colorado State University hurricane researcher Phil Klotzbach.
The NHC said the storms were not expected to interact as the region faces an unusually active hurricane season.
“We are in unprecedented times,” Mississippi governor Tate Reeves said on Saturday as he declared a state of emergency.
“We are dealing with not only two potential storms in the next few hours, we are also dealing with Covid-19.”
A hurricane watch was issued for the New Orleans metro area, which Hurricane Katrina pummeled in August 2005.
The projected tracks from the US National Hurricane Center (NHC) pointed to both storms being in the Gulf on Monday, with Marco hitting Louisiana around midday and Laura making landfall in the same general area on Wednesday. But there was still much uncertainty.
Its entirely possible that the volatile shifts seen in the models could continue, the NHC said.
Laura was centered about 95 miles east of Port-au-Prince, Haiti, with maximum sustained winds of 45mph. It was moving west-north-west at 18mph.
Crews armed with megaphones in the Dominican capital of Santo Domingo urged residents in flood-prone areas to evacuate. The storm left more than 100,000 without water, while it snapped trees and knocked out power to more than 200,000 in neighboring Puerto Rico.
It was also whipping at Haiti, which shares Hispaniola with the Dominican Republic, and forecast to move over Cuba on Sunday night or Monday.
Officials in the Florida Keys, which Laura might pass on its route into the Gulf, declared a local state of emergency and issued a mandatory evacuation order for anyone living on boats, in mobile homes and in campers. Tourists staying in hotels were warned to be aware of hazardous weather conditions and consider changing their plans.
Marco, meanwhile, was centered about 395 miles south-south-east of the mouth of the Mississippi and was moving to the north-north-west at 13mph. It had maximum sustained winds of 70mph and could become a hurricane sometime on Sunday.
New warnings were added including a storm surge warning from Morgan City, Louisiana to Ocean Springs, Mississippi, and a hurricane warning from Morgan City to the mouth of the Pearl river. A tropical storm warning included Lake Pontchartrain in Louisiana, and metropolitan New Orleans.
Storm surge up to 6ft was forecast for parts of coastal Louisiana and Mississippi.
Louisiana governor John Bel Edwards, who declared a state of emergency on Friday, asked Donald Trump for a federal emergency declaration. The cumulative impact of these storms will likely have much of Louisiana facing tropical storm/hurricane force impacts for a much longer time than with any one hurricane, he wrote. People headed to stores to stock up on food, water and other supplies.
Both storms were expected to bring 3in to 6in of rain to areas they were passing over or near, threatening flooding.