The tropical storm, now ranked a category one hurricane, is expected to make landfall on Wednesday with torrential rain and winds up to 130 kms (81 miles) per hour, Salvador Treviño Salinas, head of the state's civil defense authority, said.
The Mexican municipalities of San Fernando, Matamoros and Soto la Marina are in the path of Hurricane Dolly. The Defense Ministry and naval forces are preparing for a large-scale relief operation.
The hurricane, building up strength as it churns through the Gulf of Mexico, is currently headed for the Texas-Mexico border. A total of 14 south Texas counties have been declared potential disaster areas.
In 1967, Hurricane Beulah, ranked category five, hit the Yucatan peninsula of Mexico, killing 58 people.