Extreme rainfall is likely in a narrow strip across the midsection of the United States this week.
Nearly 18 million people are under flood watches or warnings stretching from the Mexican border to almost the Canadian border in Michigan.
A slow-moving stationary front across the center of the country will continue to drift east over the region through Wednesday night.
“This is the dividing line between the cold air in the West and the warm air in the South,” said CNN Meteorologist Dave Hennen.
Storms will build along the front and drop inches of rain.
Some locations over the next 5 days could see as much as 6 to 8 inches of rainfall.
The most torrential rain today is expected in the Midwest, where 2 to 4 inches of rain could fall over a widespread area.
Rainfall across the US is being enhanced by the moisture from Tropical Depression Narda on the western coast of Mexico.