Hurricane Katia strengthened on Wednesday evening as it churned off the Gulf coast of Mexico before an expected turn towards land that could batter eastern states with high winds and heavy rain, the U.S. National Hurricane Center (NHC) said.

A Category 1 hurricane, Katia was 200 miles east of the port of Tampico, blowing maximum sustained winds of 80 miles per hour (129 km per hour), and may be close to major hurricane strength by the time it is forecast to hit land this weekend, the NHC said. Category 1 is the NHC's weakest hurricane designation. Category 5 is the strongest.

Storms of Category 3 and above are defined as major hurricanes. There are now three hurricanes in the Atlantic. Hurricane Irma, one of the most powerful Atlantic storms in a century and a Category 5, howled past Puerto Rico on Wednesday and is on a collision course with Florida. Hurricane Jose in the open Atlantic, some 1,000 miles (1,610 km) east of the Caribbean's Lesser Antilles islands, could become a Category 3 and eventually threaten the U.S. mainland.

Earlier in the day, Katia was slightly nearer to the Mexican coast, and at about 10 p.m. CDT (0300 GMT) was moving east-southeast at around 2 mph (4 kph), the center said. The NHC said the storm should strengthen further and would probably start drifting towards the southwest before it is forecast to hit the state of Veracruz by early Saturday.

Katia has "worrying characteristics" because it is very slow-moving and could dump a lot of rain on areas that have been saturated in recent weeks, Luis Felipe Puente, head of Mexico's national emergency services, told domestic television. State oil and gas company Pemex has installations in and around the coast of Veracruz, but the firm has not reported any interruptions to its operations.

The storm is expected to bring total rainfall of 5 to 10 inches (13 to 25 cm) over northern Veracruz, and 2 to 5 inches over southern Tamaulipas state, northeastern parts of the state of Puebla, and southern Veracruz through Saturday morning. The rains may cause flash floods and mudslides, especially in mountainous areas, the NHC said.

The flurry of storm activity comes after Hurricane Harvey killed about 60 and caused property damage estimated as high as $180 billion after pummeling the coasts of Texas and Louisiana with torrential rain and severe flooding.

Reporting by Mexico City Newsroom; Writing by Dave Graham; Editing by Lisa Shumaker and Clarence Fernandez