Flooding downpours to pivot across Mississippi, Ohio and Tennessee valleys into weekend

By Alex Sosnowski, AccuWeather senior meteorologist
August 17, 2018, 8:44:12 PM EDT

An area of downpours with a history of flash flooding will shift eastward to end this week then settle southward this weekend over the central United States.

In addition to the risk of flash flooding, a few storms will become strong enough to cause incidents of damaging winds and hail.

Heavy storms dumped inches of rain across parts of northeastern Oklahoma on Thursday afternoon, resulting in flash flooding near Stillwater and Tulsa, Oklahoma.

On Friday, Gov. Tom Wolf signed a proclamation of disaster emergency for Pennsylvania in response to recent flooding, and ahead of this weekend's rain.

The batch of rain may be welcomed in some communities but may cause problems for travel and outdoor plans.

Persistent downpours caused flooding in poor drainage areas and slow travel in part of southern Wisconsin during Friday morning. Watertown, Wisconsin, received 6 inches of rain from the storm.

Through Friday evening, torrential downpours and a few locally gusty storms will advance eastward across the Ohio Valley and Great Lakes region.

Motorists should expect travel delays.

In most areas, significant forward speed of the storms should keep downpours brief in most areas. However, it is possible the storms may repeat in some communities. Where this happens, the risk of flooding will be greatest.

Cities that may be affected by downpours and travel delays into Friday night include Indianapolis, Evansville and Fort Wayne, Indiana; Cincinnati, Columbus, Cleveland, Youngstown and Toledo, Ohio; Louisville and Lexington, Kentucky; Detroit, Nashville and Pittsburgh.

Static Rain Into Friday Night

During this weekend, just enough dry air is forecast to punch in to keep storms at bay over much of central and northern Illinois, Indiana and Ohio, as well as much of Michigan and Wisconsin.

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However, farther south, across the lower part of the Ohio Valley, Tennessee Valley and southern Appalachians, dry air will struggle to move in. Through at least Saturday, downpours are likely to linger, repeat and potentially cause flash flooding in these areas.

Static East Rain Saturday 8 am

There is a chance that enough dry air mixes in on Sunday to turn off showers or at least cause them to be much more spotty with the exception of the lower Mississippi Valley and Delta.

Farther west on Sunday, a new batch of showers and thunderstorms is forecast to move eastward across the Plains and increase in intensity.

Download the free AccuWeather app to stay aware of flooding dangers.

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