Miami Tropical Storm Gert came ashore Sunday in northeastern Mexico, bringing the threat of several inches of rain to areas already soaked by Hurricane Emily.
Gert's predecessor, Tropical Storm Franklin, was weakening over cooler water in the Atlantic.
Mexican officials posted a tropical storm warning for parts of the Gulf coast, stretching from Palma Sola northward to La Pesca.
"The primary threat with this system is rainfall," said Richard Pasch, a hurricane specialist at the National Hurricane Center in Miami. "And rains from Gert will reach some of the areas earlier affected by Emily, which would pose an increased flood threat."
Pasch said Gert could deliver 4 to 8 inches of rain to some areas, with isolated mountain regions receiving up to 12 inches. The rain could trigger flash floods and mudslides, he said.
Meanwhile, Franklin had weakened in the open Atlantic. With top sustained winds down to 45 mph, it was centered 410 miles west-southwest of Bermuda and drifting near 3 mph. Forecasters said a tropical storm warning might be necessary today for Bermuda.