Alberto, the first named storm of the 2024 Atlantic hurricane season, expected to make landfall in north Mexico on Thursday.
The storm was located about 185 miles (300 kilometres) east of Tampico, Mexico, packing maximum sustained winds of 40mph (65km/h), the Miami-based forecaster said on Wednesday.
Alberto, which is bringing strong winds, heavy rainfall and some flooding along the coasts of Texas and Mexico, is expected to make landfall in northern Mexico on Thursday.
“The heavy rainfall and the water, as usual, is the biggest story in tropical storms,” said Michael Brennan, director of the NHC.
Brennan said that winds could get up to 45mph (72km/h) to 50mph (80km/h) before the storm makes landfall.
As much as five inches (13 centimetres) to 10 inches (25 centimetres) of rain was expected in some areas along the Texas coast, with even higher isolated totals possible, Brennan said.
He said some higher locations in Mexico could see as much as 20 inches (50cm) of rain, which could result in mudslides and flash flooding, especially in the states of Tamaulipas, Coahuila and Nuevo Leon.
The storm was moving west at nine miles per hour (15km/h). Tropical storm warnings were in effect from the Texas coast at San Luis Pass southward to the mouth of the Rio Grande and from the northeastern coast of Mexico south of the mouth of the Rio Grande to Tecolutla.
“Rapid weakening is expected once the centre moves inland, and Alberto is likely to dissipate over Mexico” on Thursday, the NHC said.
The US National Weather Service (NWS) said the main hazard for southern coastal Texas is flooding from excess rain. On Wednesday, the NWS said, there is “a high probability” of flash flooding in southern coastal Texas. Tornadoes or waterspouts are possible.