Tropical Storm Barbara has been upgraded to a hurricane as it bears down on southern Mexico's Pacific coast
The U.S. National Hurricane Center
in Miami said Barbara's maximum sustained winds have increased to more than 120 kilometers per hour.
A hurricane warning has been issued for the area in the Gulf of Tehuantepec from Puerto Angel to Barra de Tonala.
The first hurricane of the year is forecast to bring heavy rains and a storm surge of more than one meter.
Barabra is centered south of Salina Cruz, Mexico, the site of Mexico's largest oil refinery, and is expected to lose strength when it makes landfall in a few hours.