More heavy rain is set to batter Mexico's southern coast as Tropical Depression Eleven-E strengthens, the U.S. National Hurricane Center said on Thursday, warning of potential flooding and mudslides in areas already soaked by recent storms.

A tropical depression could form in a few days while a system of low pressure is over the southern Gulf of Mexico or northwestern Caribbean Sea.

Whether it becomes a named storm or not, the system could bring heavy rain to the Florida peninsula and potentially elsewhere starting around Sunday.