Updated

Tropical Storm Franklin crossed the Yucatan Peninsula on Tuesday and moved out into the open sea, with forecasters predicting it would strengthen into a hurricane before making a second landfall on Mexico's central Gulf coast.

The U.S. National Hurricane Center said the storm's center was 325 miles (525 kilometers) east-northeast of Veracruz late Tuesday and it was heading west-northwest at 10 mph (17 kph).

Franklin began gaining strength after getting over open water again, with its maximum sustained winds rising to 50 mph (85 kph). The hurricane center predicted it would gain more power as it moved across the lower reaches of the southern Gulf of Mexico and be a hurricane by the time it moved ashore late Wednesday or early Thursday.

A hurricane watch was in effect along the Mexican coast from Veracruz to Tuxpan. A tropical storm warning was posted from Veracruz east to Celestun and from Tuxpan north to Rio Panuco. Tropical storm-force winds extended up to 185 miles (295 kilometers) from the center.

Mexico Civil Protection director Ricardo de la Cruz said earlier that the storm's impact in Yucatan was not as bad as initially feared, with some trees down and power out in some areas.

But, he warned, "The second impact could even be stronger than the first."

Franklin's rains posed the threat of flash floods and mudslides in the mountains of central Mexico.

Four to eight inches (10 to 20 centimeters) of rain were forecast for mainland areas in the storm's path, with localized amounts of up to 12 inches (35 centimeters).