Widespread flooding caused by rain storms has left several people dead in southern Missouri and northwest Arkansas. (The Washington Post)

After 10 to 15 inches of rain in the past seven days, much of southern Missouri and northern Arkansas is underwater. So much precipitation has fallen that major rivers have spread well beyond their banks. Muddy brown water is at the rooftops in the hardest-hit communities.

On Wednesday, the Black River breached a levee near Pocahontas, Ark., prompting a flash-flood emergency for the town as thousands of gallons of water rushed through the gap.

“Residents should evacuate immediately in east Pocahontas and points southeast in Randolph and Lawrence counties,” the Weather Service wrote in a bulletin. “Expect a rapid increase in water depths and flowing water. Businesses … homes … and any structures will flood. This is a potentially life threatening situation.”

Then the Black River overwhelmed the city of 6,500; emergency responders had to rescue people from their flooded homes and cars. More than 20 people have died in the Midwest since the flooding began over the weekend.

The scene is already unbelievable, and there’s more rain moving in on Wednesday. Through the end of the week, an additional five inches are possible in southern Missouri and Illinois.

Weather.com is rigorously tracking river flood stages up and down the Mississippi and its feeder rivers. As of Wednesday afternoon, it reported 14 locations that set new water level records, 12 of which have been in Missouri.