Flash flooding is likely from parts of the Gulf Coast into the Southeast and parts of the mid-Atlantic as a low-pressure system that moved inland on Sunday night has collided with a stalled cold front bringing heavy rain and thunderstorms to the region.
The cluster of showers and storms showed little signs of development and was given a 10% chance of becoming a tropical system.
Since moving inland, those chances have dropped to 0%.
Many cities will have another shot of flooding rains on Tuesday.
As the system advances farther to the north and east, several inches of rain are expected to fall.
In terms of totals, parts of northeastern Alabama, northwestern Georgia and southwestern Tennessee could pick up 3 to 5 inches of rain through Tuesday morning.
That's where the heaviest rain and thunderstorm activity is expected to occur.
The heaviest rain is expected in the Tennessee and Ohio valleys and parts of the mid-Atlantic.
And as heavy rain, thunderstorms and gusty winds move across the region, flash flooding will become a concern.
Flash flooding is possible along the Gulf Coast from Louisiana to the Florida Panhandle, and to the north through the Southeast and into southern areas of the mid-Atlantic.
Millions of Americans are at risk of severe weather on Tuesday, with most of those at risk residing in Texas and parts of the southern High Plains.
However, severe weather is also possible along the Florida Panhandle, parts of eastern Alabama, most of Georgia, South Carolina and southern North Carolina as the low-pressure system continues to spin its way to the north and east.