The Houston, Texas area is under the threat of worsening flood conditions Saturday, a day after heavy storms pummeled the region.

Authorities have warned those in low-lying areas to evacuate ahead of an expected “catastrophic” surge of water.

A flood watch remains in effect through Sunday afternoon as forecasters have predicted more rainfall Saturday night, which could bring another 8 centimeters of water to the drenched region and with it, the likelihood of major flooding.

Friday’s storms resulted in multiple high-water rescues, including some from the rooftops of flooded homes.

Officials are imploring residents in low-lying areas to evacuate, warning the worst is still to come.