By Alex Sosnowski, AccuWeather senior meteorologist
May 16,2017, 12:08:50PM,EDT
As rounds of thunderstorms repeat in portions of the Plains and Mississippi Valley, the potential for dangerous flooding will increase into this weekend.Violent thunderstorms will not be the only threat over a large part of the central United States into this weekend.
"In places that have wet ground now, any additional rain will aggravate flooding and delay planting operations," according to AccuWeather Chief Meteorologist Elliot Abrams.
Motorists should be prepared to turn around if they encounter flooded roadways.
In the short term, areas from central Kansas to eastern South Dakota, central Minnesota, northern Wisconsin and the Upper Peninsula of Michigan will be at risk for flash and urban flooding into Wednesday.
A general 1-2 inches of rain will fall in this area with local amounts to 4 inches possible.
As the week progresses, the greatest risk of flooding ranging from urban areas to small streams and perhaps rivers will shift farther south and east.
During Thursday and into Friday, a new storm will slice northeastward across the central and southern Plains. The potential for torrential downpours will accompany and extend beyond the area of severe weather.
"The area from part of central Texas to central Oklahoma, central and eastern Kansas, southeastern Nebraska and part of Missouri will receive enough rain to cause an elevated risk of flash and urban flooding," according to AccuWeather Meteorologist Evan Duffey.
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A general 2-4 inches of rain is likely with the potential for local amounts to 6 inches over the span of 24 to 72 hours, which will cause water to collect in poor drainage areas.
"As this water runs off the saturated soil, the potential for small stream flooding will increase, followed by a significant rise on some of the area rivers," Duffey said.
The forward motion of this storm system may grind to a halt this weekend.
Showers and thunderstorms are likely to continue to erupt along the boundary between cooler air to the northwest and warm, humid air to the southeast.
Exactly where this boundary or highway of moisture sets up will determine which areas from the southern Plains to the middle Mississippi Valley will be at greatest risk for flooding during the weekend.
A lack of rain in part of this area over the past week may limit renewed major flooding on the large rivers, where water has receded below flood stage.
However, some rise in water levels is likely on the secondary rivers. Even if new river flooding does not occur in this area, the potential for flash, urban and small stream flooding will remain high due to the moist state of the ground.
The additional rainfall could be enough to slow the rate of recession for a few days on some of the largest rivers in the region, including the Mississippi and White rivers.
Even in the absence of rain over the next week, the White River at Des Arc and Clarendon, Arkansas, and the Mississippi River at Osceola, Arkansas, are projected to remain above flood stage into the last week of May.
At Vicksburg, Mississippi, the Mississippi River is projected to crest at moderate flood stage this weekend. Farther downstream, at Baton Rouge, Louisiana, the Mississippi will reach major flood stage and is not expected to crest until next week.
High water levels on the Mississippi will continue to affect some port operations and barge traffic through the end of the month.