Several viewers sent Eyewitness News videos of the waterspout.
The La Porte Office of Emergency Management tweeted, "Take cover if near this area."
Funnel cloud spotted near Sylvan Beach and heading south toward Shoreacres. Take cover if near this area. #houwx— La Porte OEM (@lpoem) July 17, 2017
The National Weather Service has issued a marine warning.
Meteorologist Casey Curry said heavy rain and lightning are the biggest concerns for the afternoon in the Houston area and down toward the coast.
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