By Kristina Pydynowski, AccuWeather senior meteorologist
July 15,2017, 11:18:00PM,EDT
Additional rounds of thunderstorms will take aim at the Upper Midwest this week, threatening to turn severe and further heightening the flash flood danger.
After isolated severe weather in Wisconsin late Saturday, the Upper Midwest will welcome a comfortable end to the weekend.
The risk for locally gusty thunderstorms will shift to the corridor from Detroit and Toronto to Indianapolis later on Sunday, while great weather for outdoor plans greets residents from Fargo, North Dakota, to Minneapolis to Madison, Wisconsin.
The turn to calm and dry weather will not last long.
Steamy air will quickly surge back across the Upper Midwest on Monday, setting the stage for thunderstorms to erupt from Minnesota and eastern North Dakota to Nebraska in the afternoon and evening.
“Hail, damaging winds and locally heavy rain are the main hazards,” Brown said.
Residents in Fargo; Aberdeen, South Dakota; and Duluth, Minnesota, will have to keep an eye to the sky and be prepared to seek shelter.
This zone of thunderstorms will continue to press to the south and east through Wednesday.
“The morning drive to work on Tuesday morning can feature a soaking rain along the I-35 and I-94 corridors of Minnesota,” Brown said.
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The stormy weather will also return to Green Bay, Wisconsin, and Des Moines, Iowa, on Tuesday and Detroit on Wednesday.
However, a strong push of dry air will not sweep in behind these thunderstorms.
Instead, additional rounds of thunderstorms will ignite over the northern Plains and track to the Great Lakes into later in the week.
Each bout of thunderstorms will likely bring the risk for at least localized severe weather. The areas at risk each day will depend on exactly where fronts settle, as well as lingering showers/cloud cover from the previous day’s thunderstorms.
“Even beginning on Tuesday afternoon, low pressure developing over the central Plains can work to ignite severe thunderstorms,” Brown said.
The heaviest thunderstorms each day could also drop a quick 1-2 inches of rain with locally higher amounts in a matter of a few hours. Where these thunderstorms repeat over the same areas, flash flooding may threaten lives and property.
“By the time the third round of thunderstorms track through the Upper Midwest on Wednesday night, areas that have seen heavy rain earlier in the week will be especially vulnerable to flash flooding,” Brown said.
This concern will only expand to more communities as additional downpours follow later in the week.
Southeastern Wisconsin and northeastern Illinois are already more susceptible to new or aggravated flooding after heavy rain this past week left the ground saturated and rivers running high.
Major river flooding continues on the Fox and Des Plaines rivers.
On Saturday, the Des Plaines River near Gurnee, Illinois, rose above its previous record crest of 11.95 feet from Sept. 27, 1986. Water levels are forecast to slowly decline on these rivers next week.
On the other hand, the Dakotas and parts of Nebraska and eastern Montana are in need of rain.
An extreme drought is currently plaguing the Missouri River valley from northern South Dakota to eastern Montana, according to the United States Drought Monitor.
The rounds of thunderstorms may develop far enough to the west to help ease these conditions.