Tropical moisture streaming into the central Plains from the tropical systems in the East Pacific Ocean will help to fuel locally severe thunderstorms and flooding downpours across the region into Sunday night.
Drenching rain developed across the Dakotas and northern Minnesota Friday evening and continued into Saturday morning as a storm system began to strengthen over the region.
Heavy rain over North Dakota and northwest Minnesota has lead to totals of 5 to 7 inches of rain. This map is radar estimated so if you have seen higher let us know! #ndwx #mnwx pic.twitter.com/lSnpVAJdcO— NWS Grand Forks (@NWSGrandForks) September 21, 2019
Residents woke up to flooded roadways as over five inches of rain fell in Grand Forks, North Dakota, Friday night. Radar-estimated rainfall shows similar rainfall totals across much of the area.
Grand Forks normally receives 2.05 inches of rain through the month of September.
Downpours erupted farther south on Saturday afternoon and evening, targeting a corridor from northern Kansas to southwestern Iowa.
The storm system that soaked the northern Plains to begin the weekend will continue to slowly sag southeastward into Sunday night. Tropical moisture from Lorena and Mario will be pulled northward into the central Plains, enhancing rainfall across the region.
Through Sunday evening, downpours will soak the same areas of the central Plains that were hit late Saturday. But as tropical moisture was also pulled farther north, bringing drenching rain into Illinois, Iowa and Michigan.
Flash flooding will be most common in areas where the front stalls and brings multiple rounds of heavy rain into Sunday evening.
"This will have the ability to produce widespread rainfall totals of 1-3 inches with an AccuWeather StormMax™ of 6 inches," AccuWeather Meteorologist Tyler Roys said.
Chicago; Green Bay; Kansas City and Springfield, Missouri; and Oklahoma City are forecast to be in the heavy rain area.
Those heading outdoors on Sunday will need to be aware of possible road closures due to flooding and pack rain gear.
A line of locally heavy showers and thunderstorms along the cold front will begin to push south out of the central Plains Sunday night, while the bulk of the rain spreads into parts of the Ohio Valley.
The storm system will move toward the Northeast on Monday and drier air will settle into the northern and central Plains for the start of the work week.