Beaumont police and Carbin said a third tornado was spotted in Beaumont, but did not cause any damage. Downed trees and small hail were reported in East Texas.
"That's what it takes is that contrast between the cold very dry air and the warm moist air that is readily available or at least never far away from the Texas Gulf Coast," Carbin said.
At the storm system's peak, 21 counties in Texas, including the city of Houston, were under a tornado watch.
Centerpoint Energy listed on its website that more than 20,000 customers remained without power in the Houston area just before 4 p.m. Entergy reported on its website that nearly 20,000 of its customers in East and Central Texas, as well as parts of Louisiana, were without power.
Associated Press writer Janet McConnaughey contributed to this report from New Orleans.
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