With more heavy rain forecast through at least Wednesday, residents and emergency officials throughout the Ohio and Mississippi River valleys are preparing for flooding that a Kentucky meteorologist says could be catastrophic.

Emergency management officials in Missouri say they aren’t sure exactly how many people are being moved out of harm’s way in Poplar Bluff, a town with 17,000 residents about 150 miles southwest of St. Louis. But police say they believe a catastrophic failure of the levee is imminent.

Meanwhile people in flood-prone parts of Kentucky have begun packing their belongings.