Tropical Storm Barbara, swirling off the southwestern coast of Mexico, could strengthen over the next few days to become the Pacific's first hurricane, forecasters predicted.

At 2 a.m. PDT Thursday, the storm was about 210 miles south-southwest of Puerto Angel in Oaxaca state. It had winds of 45 miles per hour and was moving south-southeast at about 2 miles per hour.

The U.S. National Hurricane Center said Barbara could gain hurricane strength by late Saturday night and advised that "interests along the Pacific coast of southeastern Mexico and Guatemala should closely monitor the progress of Barbara."

The center said the storm could reach the Mexican coast on Sunday.

Mexico's National Meteorological Service said the storm could bring "intense rain that can generate landslides in mountainous zones, as well as floods in coastal and low zones."