Tropical Storm Barrymade landfall north of Mexico's major Gulf Coast port of Veracruz on Thursday morning and was heading inland, unleashing rain showers and wind gusts, but installations of state oil monopoly Pemex were unaffected.

The storm is likely to lose strength as it moves west, the U.S. National Hurricane Center said in an advisory.

Two of Mexico's three major oil-exporting ports - Dos Bocas and Cayo Arcas - remained closed, but Coatzacoalcos has reopened, the nation's Communications and Transport Ministry said.

Those three ports and Veracruz had been closed starting Wednesday afternoon as the storm approached the coast.

Almost all of Mexico's crude oil exports, which totaled 1.275 million barrels per day in April, are shipped to refineries on the Gulf Coast of the United States from the ports of Coatzacoalcos, Dos Bocas and Cayo Arcas.

Veracruz is home to the Minatitlan refinery, Pemex's fifth-largest and the most recently modernized. It has the capacity to produce 245,000 barrels per day.

Pemex also has three petrochemical complexes and three gas processing complexes in Veracruz.

Asked about the state of Pemex's installations in the Gulf of Mexico, a company official texted: "Everything is OK."

Maximum sustained winds had decreased to 40 miles per hour (64 km/h).

The National Hurricane Center said it expected 3 to 5 inches of rainfall, with maximum accumulations of 10 inches over portions of southern Mexico. Tropical storm winds will probably continue for several hours and subside later Thursday, the center said.