The airfields, George Bush Intercontinental Airport and William P. Hobby Airport, said Tuesday that they will remain closed until further notice, according to time.com.
The Federal Aviation Administration predicted that services at Bush Intercontinental could resume by Thursday, while Hobby could reopen by Wednesday. However, neither airport immediately responded to TIME’s requests for comment. (A photo circulating on social media purporting to show aircraft underwater at a Houston airport has been debunked as fake.)
As of Tuesday, the majority of flights scheduled to depart from and arrive at both airports were cancelled, according to aviation tracking site FlightAware. On Tuesday, 513 flights leaving from and 512 arriving at Bush Intercontinental were cancelled, while 158 flights leaving from and 159 flights arriving at Hobby were also cancelled. Thousands of flights in total have been cancelled because of the storm.
Many airlines were offering passengers the chance to rebook their flights ahead of the storm.
Hurricane Harvey, now a tropical storm, has resulted in at least 20 deaths confirmed by local authorities, the Associated Press reported Wednesday.
Thousands of residents have been displaced. The storm’s overall impact will only increase as it dumps additional rain on parts of Texas and Louisiana through the rest of the week.