Louisiana is bracing for what officials are warning will be a "one-two punch," as two hurricanes are expected to hit the state within 48 hours of each other.

Tropical Storm Marco, which had been gaining speed and strength as it crossed through the Gulf of Mexico, was declared a Category 1 hurricane on Sunday and is expected to make landfall Monday. Following close behind is Tropical Storm Laura, which forecasters say will be a Category 2 hurricane by the time it makes landfall within the next few days.

If the two systems develop into hurricanes simultaneously, it would be the first time on record that the Gulf of Mexico has had two hurricanes at the same time, according to Colorado State University hurricane researcher Phil Klotzbach.

With maximum sustained winds of 75 mph, Marco was on track to cross the central Gulf of Mexico on Sunday. As it approaches shore, tropical storm conditions are possible early Monday along portions of the Gulf Coast, with hurricane conditions expected by midday, according to the National Hurricane Center.

Cities from Morgan City, La. to Ocean Springs, Miss. could see a storm surge of 4 to 6 feet — especially if the peak surge occurs during high tide. Sabine Pass to Morgan City, La. could see a storm surge between 2 to 4 feet, as could the area from Ocean Springs, Miss. to the Mississippi-Alabama border.

"The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland for the shoreline," the NHC said.

Tropical Storm Laura, which has already drenched Haiti and the Dominican Republic, is moving west-northwest at 21 mph, the NHC said. It is expected to strengthen as it approaches the Florida Keys during the next couple of days and approaches Louisiana. The storm is forecast to become a hurricane late Tuesday.

Louisiana Gov. John Bel Edwards warned that the brief window of time between the storms could lead to a dangerous situation for residents.

"The temporal proximity and the geographic proximity of these storms pose a challenge that, quite frankly, we've not seen before," Edwards said Sunday. "As a result, we don't know exactly what to expect," he said, warning it's a "very serious situation."

"These storms are not to be taken lightly, especially because there are two of them, and they're going to impact so much of south Louisiana, so close together," Edwards said. The governor encouraged families to be prepared to ride out the storms wherever they are on Sunday night.

Complicating matters is the ongoing coronavirus pandemic.

"We still have a lot of COVID-19 in Louisiana, tens of thousands of cases across the state, and as many of half of which are completely asymptomatic. So that makes this a very difficult emergency to manage without having the natural disaster on top of it," Edwards said. People should continue to wear masks, keep physical distance and wash hands regularly, he said.

State officials say mass sheltering is typically not needed for hurricanes weaker than Category 3. But if mass shelters are required, officials say they are prepared to segregate by family, and will have protocols in place for thermometers and personal protective equipment in order to reduce the spread of COVID-19.

The governor urged residents to prepare to take cover, warning they will essentially be on their own for the first few days.

"The first 72 hours is on you," Edwards said. "That is because the second storm comes in so close that there may not be much of a window when we can fly search-and-rescue helicopters, when we can get out with high-water vehicles, and those sorts of things."

Characterizing the storm systems as a "one-two punch," NWS New Orleans meteorologist-in-charge Benjamin Schott urged residents to take precautions now in advance of the high winds, storm surges and likely power outages.

"Category 1 hurricanes still put a lot of people at risk to not only lose property but also their lives," Schott said. "Though the winds may not be the greatest threat, there will be a significant threat when it comes to the rainfall."

Southeast Louisiana risks a significant amount of rainfall causing flash flooding, making it dangerous for anyone who is trying to travel, Schott said.

"There will be a continuous flow of water into areas across coastal Louisiana, which will just enhance the coastal flooding even beyond Marco's reach, and into Laura's reach later on in the week," Schott said, warning that 3 to 6 foot storm surges are likely.

Marco is expected to approach Texas on Tuesday evening. At that point, Laura is expected to be a Category 2 hurricane working its way toward Louisiana.

"It may have a pretty significant wind punch," bringing a storm surge of 7 to 10 feet across southern Louisiana, Schott said.

Mississippi will also see a lesser storm surge, with continued coastal flooding from multiple days of wind pushing water inland. Both hurricanes could bring at least 5 to 10 inches of rain, with some spots in Louisiana seeing as much as 2 feet of rainfall. Both states have declared states of emergency in advance of the storms.

"There are significant impacts from these storms that go beyond the wind, and I think water is the one that we need to respect the most, whether it be at the coast with the surge of coastal flooding, or whether it be inland with the heavy rain and flash flooding," Schott said. "All of this can destroy property and take people's lives."

Edwards requested a federal emergency declaration from the White House on Saturday. As of Sunday afternoon, that request was still "pending at the White House," Edwards said.

Power companies in the state have activated their emergency response plans to prepare to restore power to customers as quickly as possible, said the Edison Electric Institute, which represents electric companies throughout the country. Offshore oil and gas operators in the Gulf evacuated platforms and rigs Saturday in preparation for the storms.

The National Guard is prepositioning personnel and high-water vehicles across southern Louisiana, including sandbags and generators, in anticipation for the storm, Edwards said, noting that 1,800 guardsmen are on drill duty and ready to provide support. The state has also been in close coordination with the Federal Emergency Management Agency, which has positioned two aid packs, each containing thousands of emergency food packets.

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