Tropical Storm Hermine is the eighth named storm of the Atlantic hurricane season [AFP]

Tropical Storm Hermine has slammed into northeastern Mexico near the Texas border, dumping heavy rain on a region still recovering from Hurricane Alex's visit in June.

Hermine, the eighth named storm of the Atlantic hurricane season, made landfall around 8:30 pm (0130 GMT) along the coast of northeastern Mexico,  about 65 km south of Brownsville, Texas, and 170 km north-northeast of La Pesca, Mexico late on Monday.

It was expected to weaken as it moved ashore but could trigger deadly flooding and tornadoes, the US National Hurricane Center (NHC) said.

There were no immediate reports of damage or injuries.

The storm's forecast path kept it away from major oil and natural gas installations in the Gulf of Mexico, and energy companies said there had been no affect on their operations.

The Miami-based hurricane center warned the storm could dump heavy rain on the coastal region and would pack a 0.75-to-1.25-metre storm surge that could cause deadly flash flooding and mudslides.

Hurricane Alex hit northeastern Mexico in July, killing 12 people and causing heavy flooding in the business capital of Monterrey. Damage from the storm was estimated at $700 million.

Hermine was expected to dump 4 to 8 inches (10 cm to 20 cm) of rain over northeastern Mexico and south Texas, with isolated maximum amounts of 12 inches (30 cm) possible, the hurricane center said.

High alert  

In the Mexican coastal city of Matamoros, residents braced for flooding as authorities remained on high alert.

At least 30 residential areas could be in danger from floods, although no evacuations had started yet, an official for the city's civil protection said.

In the Atlantic, the remnant of Tropical Storm Gaston continued to move westward and had a medium chance of reforming as a tropical cyclone during the next 48 hours.

Storm models predicted Gaston would travel almost due west, which would take it very close to Puerto Rico, the Dominican Republic and Haiti.

The hurricane season runs from June 1 through Nov. 30 and is currently in its peak period.