Scattered thunderstorms may spread into parts of east central Kansas and west central Missouri toward sunrise, according to the National Weather Service.
Areas south of a Paola, Kan., to Sedalia, Mo., line would be affected.
For Kansas City, Kan., there is a 30 percent chance of rain Friday, the weather service said.
Thunderstorms over Oklahoma and the Texas panhandle are expected to form a complex overnight and spread east and northeast, possibly reaching east central Kansas toward sunrise Friday.
The heavy rain threat has shifted south of the forecast area, the weather service said.
Friday through Wednesday, thunderstorms may be ongoing across the southern portion of the region.
A front will arrive Saturday morning. Local flooding will remain the primary concern through the end of the week.