After a day as a hurricane, Tropical Storm Marco approached Louisiana for an expected landfall around midday Monday, while Tropical Storm Laura was forecast to move along Cuba's southern coast during the day before entering the Gulf of Mexico and heading toward the same stretch of U.S. coast later in the week, most likely as a hurricane and perhaps a powerful one.
Laura caused the deaths of at least 11 people in the Dominican Republic and Haiti, while knocking out power and causing flooding in the two nations that share the island of Hispaniola.
Marco had grown into a hurricane early Sunday, but the National Hurricane Center said its sustained winds decreased to 70 mph after nightfall. The center cautioned that Marco could still cause life-threatening storm surges and dangerous winds along the Gulf Coast.
Marco was centered about 115 miles south-southeast of the mouth of the Mississippi River and heading northwest at 10 mph early Monday morning.
Laura was centered about 175 miles east-southeast of Cayo Largo overnight Monday and had maximum sustained winds of 65 mph. It was scooting west-northwest at 21 mph and was predicted to strengthen into a hurricane by Tuesday morning as it followed a path likely to take it to the Louisiana coast by Wednesday night, forecasters said.
"Houston and Galveston are still very much in the danger zone for a landfall. It's even possible we could have one as far south as Corpus Christi (Texas). Somewhere is going to get 10-15" of rain from Laura in a very short period of time," said CBS News weather producer David Parkinson.
"The farther west the storm goes, the later (landfall) it will be, and the stronger it will be," Parkinson said. "I'd expect a landfall right at Category 3 strength, but the water (in the gulf) is warm enough for a 4+. A track toward Louisiana likely nets us a Cat 2 landfall. Storm surge will be a concern with the water level really not having time to go down after Marco."
The mayor of Port Arthur, in south Texas, has ordered an evacuation beginning Tuesday at 6 a.m. local time, CBS Dallas/Fort Worth reports.
Despite Marco's weakening, a storm surge warning remained in place from Morgan City, Louisiana, to Ocean Springs, Mississippi. A tropical storm warning included Lake Pontchartrain in Louisiana and metropolitan New Orleans.
A storm surge of up to 4 feet was forecast for parts of coastal Louisiana and Mississippi.