Another tropical storm is forming close to the US coast.

Tropical Storm Hermine has formed in the Gulf of Mexico off the coast of Texas, causing the National Weather Service to issue a warning for the south Texas coast from the mouth of the Rio Grande to Baffin Bay.

A tropical storm warning has already been issued for the coast of Mexico from Tampico to the mouth of the Rio Grande.

The storm is expected to bring heavy rain into northeastern Mexico and south Texas, with warnings of flash floods and mudslides.

The storm is located about 235 miles southeast of La Pesca, Mexico, and is moving north.