Although the appearance of two tropical storms simultaneously aimed at the Louisiana coast launched a torrent of memes, it looks like one has already faded.
According to the latest updates from the National Hurricane Center, Tropical Storm Marco is not expected to cause any weather problems in our region tonight or tomorrow. On the other hand, Tropical Storm Laura is expected to make landfall between southeast Texas and south central Louisiana as a dangerous Category 2 hurricane late Wednesday or early Thursday.
In its 10 p.m. update, the NHC said Marco made landfall around 6 p.m. Monday near the mouth of the Mississippi River. Reports from an Air Force Reserve Hurricane Hunter flight found that the storm was still producing a small area of tropical-storm-force winds over water to the northeast of its center. But since then, Marco has moved almost due west along the coast while its deep convection has become farther displaced from the low-level center. Between the lack of central convection and Marco's proximity to land, it is likely that the winds have decreased since earlier this evening and the intensity has been lowered to 30 knots.
If deep convection does not redevelop overnight, Marco will become a remnant low as soon as Tuesday morning. Regardless of its status, Marco should move generally westward while it weakens for the next day or so. It could continue to produce heavy rain for portions of the north-central Gulf Coast tonight.
The system is forecast to dissipate by early Wednesday, if not sooner.
At the same time, tropical storm conditions and heavy rainfall are expected across central and western Cuba for several more hours as Tropical Storm Laura rakes the island. These rains could cause mudslides and life-threatening flash and urban flooding.
Laura is forecast to reach hurricane status early Tuesday. It is expected to make landfall somewhere along the northwestern Gulf Coast as a hurricane late Wednesday or early Thursday. Even as the storm’s track remains unsettled, storm surge, wind, and rainfall hazards are expected to extend well away from Laura's center along the coast.
Forecasters said there is a risk of life-threatening storm surge from San Luis Pass, Texas, to Ocean Springs, Miss., within the next 48 hours. A storm surge watch is in effect for these areas outside of the southeast Louisiana Hurricane and Storm Damage Risk Reduction System. Hurricane conditions are possible by late Wednesday anywhere from Port Bolivar, Texas, to west of Morgan City, with tropical storm conditions possible by Wednesday afternoon. A hurricane watch is in effect, and additional hurricane watches may be needed farther south along the Texas coast if the track forecast shifts toward the south and west overnight and into Tuesday.
According to the NHC’s 10 p.m. update, hurricane force winds will be possible across the region starting late Wednesday and continuing Thursday.
At the coast, storm surge could stack water more than 10 feet above ground level. Depending on where Laura makes landfall, storm surge can back up rivers and bayous and flood over 30 miles inland. Depending on where the rain bands form, the storm is expected to bring 5 to 10 inches of rain, with local amounts of 15 inches possible starting Wednesday into Thursday.
Tornadoes will be possible in the eyewall as the hurricane approaches the coast, as well as outer rain bands starting Wednesday into Thursday.