Tropical Storm Laura, Marco head toward Gulf states

Tropical Storm Laura and Tropical Storm Marco are both expected to travel toward the Gulf of Mexico in the next few days, with both storms likely to impact parts of the U.S. coast by the early half of next week.

Marco and Laura are not expected to become hurricanes at the same time. Marco currently is forecasted to become a hurricane Saturday night until Monday morning. Laura is forecasted to become a hurricane Tuesday and Wednesday.

While it is too early to determine the exact magnitude and location of U.S. mainland impact from Marco and Laura, parts of the U.S. Gulf Coast from Texas to Mississippi may see impact from two different tropical systems in the upcoming week.

Louisiana and Mississippi have both already declared states of emergency in anticipation of the storms.

The last time there were two tropical cyclones in the Gulf was in 2002, where Tropical Storm Fay was off the Texas coast, and Tropical Depression Edouard was off the Florida west coast, according to the National Oceanic and Atmospheric Administration.

Tropical Storm Laura

Tropical Storm Laura has winds of 50 mph Saturday evening and was 125 miles east-southeast of Santo Domingo, Dominican Republic. The storm is moving west at 18 mph.

A tropical storm watch is now in effect for the Florida Keys and portions of the central/southeastern Bahamas. A tropical storm warning remains in effect from Puerto Rico through Hispaniola and for much of Cuba.

Laura brought heavy rain and gusty winds to parts of Puerto Rico and the U.S. Virgin Islands Saturday. The center is passing just to the south.

Laura is forecast to go near or over Hispaniola and Cuba over the 48 hours and this could significantly impact the storm's strength and structure. Depending on how it holds together, its strength moving into the Gulf of Mexico will be greatly impacted. But as of now, the latest forecast calls for strengthening once in the Gulf of Mexico, reaching hurricane strength as it closes in on the U.S. Gulf Coast.

On the current forecast track, Laura will move near Hispaniola on Saturday afternoon and night, and then near Cuba on Sunday.

Tropical storm force winds extend up to 205 miles from the center, mainly on the northern side of the storm. Wind gusts over 45 mph will be possible in Puerto Rico and the U.S. Virgin Islands in the next few hours.

Laura is expected to bring up to 8 inches of rain from Puerto Rico to Cuba. This could result in mudslides and flash flooding. Puerto Rico got hit pretty hard by Isaias just a few weeks ago with major flash flooding.

The track and intensity of Laura remain somewhat uncertain as we get into next week since Laura could interact with quite a bit of land this weekend.

Laura is expected to reach the Gulf on Tuesday.

Tropical Storm Marco

Tropical Storm Marco has been strengthening much of the day and getting better organized. Sustained winds were at 65 mph Saturday night and it was moving north-northwest at 13 mph. The center was about 50 miles wast of Cuba.

A hurricane watch is in effect from Intracoastal City, Louisiana, to the Mississippi/Alabama state line. A tropical storm watch has been issued for the Alabama coast with storm surge watches along portions of the northern Gulf Coast as well. Marco is forecast to strengthen into a hurricane Saturday night.

Tropical storm warnings remain in effect across portions of the Yucatan Peninsula and western Cuba Saturday.

Marco is forecast to continue to strengthen over the next 24 hours and likely become a hurricane by Saturday night. However, atmospheric conditions will be much less favorable as the storm nears the Gulf Coast. Weakening is expected ahead of any landfall.

Marco is expected near the Yucatan Peninsula later Saturday and then move into the Gulf of Mexico on Sunday. The storm will then move northward and likely turn northwest as it moves towards the U.S. coast by Tuesday.

Tropical storm force winds extend 70 miles from the center. Locally, up to 10 inches of rainfall will be possible in the Yucatan Peninsula, which could result in flash flooding.

It is still too early to determine the location and magnitude of the impacts Marco will bring to the U.S.

While it's unclear what the storms will bring, Louisiana's St. Bernard Parish, southeast of New Orleans, is already making sandbags available to residents.

"I am very proud of the way the residents of St. Bernard Parish have rallied together in the face of this weather event. The effort we have seen today by both residents and parish employees with the new sandbagging procedures has been exceptional," said Parish President Guy S. McInnis in a statement.

ABC News' William Mansell and Mark Osborne contributed to this report.