Hurricane Harvey "is going to be a very major disaster," Texas Governor Greg Abbott told reporters on Friday.
Abbott said that during a conference call, he and officials discussed "record flooding at multiple locations ranging all the way from the Corpus Christie area all the way up to the Houston area."
He told residents to "strongly consider" evacuating. Abbott also told reporters that he issued a "major disaster declaration to the president" that he hopes will trigger additional assistance from the federal government.
Businesses closed and lines of cars streamed out of coastal towns as officials called for residents to evacuate ahead of Hurricane Harvey, expected to arrive about midnight as the most powerful storm to hit the US mainland in more than a decade.
The hurricane is forecast to slam first near Corpus Christi, drop flooding rains along the central Texas coast and potentially loop back over the Gulf of Mexico before hitting Houston, some models showed.
The storm has disrupted some of the region's oil production and refining operations, sending gasoline prices higher. Some 4 percent of US refinery capacity and nearly 10 percent of offshore oil production was halted. Some inland shale oil producers ceased operations as a precaution against expected flooding.
Gas stations and grocery stores in the region were packed as residents readied their cars and pantries for any shortages following the storm.