Potentially Catastrophic Flooding From Historic Rainfall And Severe Weather Expected In Mid-South, Ohio Valley

A particularly dangerous flooding event is expected from the mid-South into the Ohio Valley as multiple bouts of extreme rainfall, including severe thunderstorms, impact parts of Arkansas, Tennessee, Missouri, Kentucky, Illinois, Indiana and Ohio.

What's Happening Right Now

As you can see in the current radar image below, areas of heavy rain extend from the Ohio Valley to the Southern Plains. Any National Weather Service watches and warnings are also plotted on the map.

Flooding has been reported on roads in parts of Kentucky this morning. A man was rescued off the roof of a submerged vehicle near Louisville, according to a National Weather Service storm report.

(MORE: Recent Updates On Flooding, Severe Weather)

Flooding Forecast

-What's Happening: A frontal system has stalled over the Southeast, and with Gulf moisture feeding northward, a serious multiday flood threat has begun.

-Where And When: Multiple rounds of rain will soak an area from northeast Texas to portions of the Mississippi and Ohio valleys into the weekend. That includes Little Rock, Arkansas; Memphis, Tennessee; Paducah and Louisville, Kentucky; Cincinnati and many other cities.

Flood watches have been issued by the National Weather Service across these regions, which means flooding is possible for multiple days. Embedded in this area is a "particularly dangerous situation" flood watch for much of Arkansas and neighboring parts of Tennessee, southern Illinois, southwest Indiana, and western Kentucky.

-How Much Rain: Potentially historic rainfall totals are possible from the Ozarks into the mid-South and mid-Mississippi and lower Ohio valleys. Rainfall totals over a half-foot are likely and some areas will likely reach double-digits, possibly up to 15 inches when all has fallen.

According to the National Weather Service in Little Rock, Arkansas, this rainfall over four days in Arkansas "is an event that happens once in a generation to once in a lifetime."

-Impacts: Both flash flooding and flooding of rivers, creeks and streams will occur. Several rivers are expected to reach major flood stage and could rise to near record levels in some tributaries, but not either the mainstem Mississippi or Ohio Rivers.

According to the NWS Paducah, Kentucky, office, "Flooding may occur in homes, businesses and other locations not normally subject to flooding." And this river flooding is likely to last well into next week, perhaps the following week as all this water drains through the river basins.

NOAA's Weather Prediction Center has issued three days of consecutive rare high risks for flooding from Thursday night through Saturday and Saturday night. NOAA found that one-third of flood-related fatalities and 80% of flood-related damage in the U.S. happens on these high risk days.

-What To Do: If you encounter a flooded road, never attempt to drive through it. It only takes about 1 foot of water to float a car or small SUV. Once your vehicle floats, you've lost control. Not only that, the road under the floodwaters may have been washed away.

If you live in a flood-prone area, be sure to stay alert for the latest National Weather Service flood watches and warnings and know where to quickly head to higher ground if needed. Follow the advice of local officials if you are ordered to evacuate.

"Communities in the region should prepare for possible long duration and severe disruption to daily life," wrote NOAA's Weather Prediction Center in a forecast discussion Thursday morning.

Severe Thunderstorm Forecast

Unfortunately, a threat of severe thunderstorms is also in play over many of the same areas with a high flood risk into the weekend.

Large hail, tornadoes and damaging thunderstorm wind gusts are possible with each round of severe weather. With increasingly soaked ground, the threat of downed trees will also increase.

On Friday, there is a higher threat of tornadoes in parts of northeast Texas and much of Arkansas. Some tornadoes in this area, which includes Little Rock, could be strong (EF3+).

Below we have the latest severe thunderstorm forecast maps for the next few days. The darker contours indicate areas where severe thunderstorms are more likely each day.

When Will It End?

While some rain and storms may linger in the Southeast Monday, a sharp pattern change with the jet stream should put an end to this siege of heavy rain and severe thunderstorms next week.

However, as mentioned earlier, river flooding in the affected areas will likely last well into next week, if not into the following week.