The storm spared major tourist areas on the Yucatan coast from a direct hit and landed in sparsely populated low-lying jungle late on Tuesday. It made land as a Category 1 hurricane, the lowest on the five-step Saffir-Simpson scale, and was downgraded to a tropical storm early on Wednesday.

Ernesto was moving toward the west and this general motion, accompanied by fluctuations in forward speed, is expected to continue for the next 24 to 36 hours, the U.S. National Hurricane Center in Miami said at 11 p. m. EDT (000 3 GM T).

"The center of Ernesto will move across the extreme southern Bay of Campeche tonight and early Thursday," the center said. State oil company Pemex has port facilities and offshore platforms in the area.

The Mexican government issued a hurricane warning for the Gulf coast from Veracruz to Chilitepec. A tropical storm warning was also issued from north of Veracruz to Barra de Nautla.

Ernesto was located 15 miles ( 2 5 km) north of Ciudad del Carment in the state of Campeche. Hurricane conditions were possible again by Thursday as the storm approaches the Gulf coast, the center said.

Mexico closed its three major oil export ports on the Gulf of Mexico - Coatzacoalcos, Cayo Arcas and Dos Bocas - port authorities said.

Almost all of Mexico's crude oil exports are shipped to refineries on the Gulf Coast of the United States from the three ports.

"The prognosis is to be operational again on Thursday," said Dos Bocas official Guadalupe Perez. "But we don't know when it will open. It depends on the size of the waves."

The storm looked set to sweep the Minatitlan refinery, which processes 185,000 barrels per day.

OIL FIELDS OPERATING NORMALLY

A Pemex representative said all the company's facilities in the area were operating normally, including the oilfields of Cantarell and Ku Maloob Zaap, which account for just over half of Mexico's oil production of about 2.5 million bpd.

Ernesto's top sustained wind speed rose to 65 miles per hour (1 00 km per hour) on Wednesday evening.

Winds blew down trees and knocked out power in some small towns in Campeche state, a civil protection official said.

Authorities in Veracruz said they were preparing emergency shelters, if needed, in the flood-prone and densely populated state.

The storm landed on the Mexican coast near the port town of Mahahual, 40 miles (65 km) north of Chetumal, the capital of Quintana Roo state. Ernesto passed well south of the major tourist resort of Cancun, which saw only heavy rains.

Several convoys of federal police and marines arrived at Mahahual, which was severely damaged by hurricane Dean in 2007, to help repair fallen electricity lines and assist local residents.

"There is a lot of damage. The windows, the roof upstairs, everything is destroyed," said Anabel Meneses, 36, a restaurant owner in the port as she recalled her business bustling with clients watching an Olympics soccer match only two days earlier.

About 2,500 people were evacuated from Chetumal up the coast to Tulum in an area known for its scuba diving and eco-tourism attractions.

Some 90 people took shelter in a high school in Chetumal, where the storm flooded streets and knocked down trees.

Rainfall of 4 to 8 inches (10 to 20 cm), and possibly 12 inches (30 cm) in some areas, was expected in the states of Tabasco, Veracruz, Puebla and northern Oaxaca through Friday, the center said.

August and September are usually the most active months of the Atlantic-Caribbean hurricane season, which runs from June 1 to November 30.

(Additional reporting by Isela Serrano in Cancun and Liz Diaz Gabriel Stargardter in Mexico City; Editing by Eric Walsh and Christopher Wilson)

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