Serious flooding risk to extend from Louisiana to Carolinas, Virginia and West Virginia

By Alex Sosnowski, AccuWeather senior meteorologist

Through this weekend, the risk of flooding rainfall will extend from the lower Mississippi Valley to the Tennessee and Ohio valleys as well as the southern Appalachians.

While it will not rain continuously in this zone, two big rounds of rain are expected to cause trouble for residents and travelers in the region.

Rainfall over much of this swath since the late autumn has averaged 1.5 to 2 times that of normal. In recent weeks, much of the area from Arkansas to southern Ohio and Kentucky has received 6-12 inches of rain.

As a result of the rainfall and low evaporation rates this time of the year, the ground is saturated.

Streams and rivers are already running high. Gauges along much of the Ohio and lower Mississippi rivers are indicated water levels above flood stage. In some cases, water levels along portions of these rivers, as well as sections of the Tennessee River are forecast to reach major flood stage from this week to next week.

While levees and even dams in some cases will help to mitigate the situation. Unprotected areas along the major rivers will take on water and may be under water for an extended period due to the overall size of these large water ways.

Urban flooding is also a concern from both the storm at midweek and then another storm this weekend.

Cities that may be hit by both storms and experience flash flooding include Nashville, Memphis and Knoxville, Tennessee; Paducah, Louisville and London, Kentucky; Huntington, West Virginia; Cincinnati; Evansville, Indiana; Cairo, Illinois; Cape Girardeau, Missouri; Little Rock and Jonesboro, Arkansas; Greenville, Mississippi; and Monroe and Baton Rouge, Louisiana.

Atlanta; New Orleans; Birmingham, Alabama; and Charlotte, North Carolina, are among the long list of cities that may receive enough rain to experience minor travel delays and perhaps localized flooding from the first storm.

The bulk of the rain will ramp up over the lower Plains and part of the lower Mississippi Valley on Tuesday, then spread northeastward to the Ohio and Tennessee valleys and the southern Appalachians during Tuesday night and Wednesday.

"A general 4-8 inches of rain is forecast with an AccuWeather Local StormMax™ of 10 inches forecast from the midweek storm alone," according to AccuWeather Senior Meteorologist Kristina Pydynowski.

What the region needs is an extended period of perhaps several weeks to get out of the flooding situation. However, there are no signs of such a long break from storms with significant rain.

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AccuWeather 2019 US spring forecast

"The pattern may trend less rainy with rain falling less often for a time at the end of the month to early March," according to AccuWeather Long-Range Meteorologist Max Vido.

The main storm track and localized flooding rainfall may shift toward the central Gulf coast during early March.

"However, as the storm track shifts northward during the spring, we may get a revival of frequent heavy rain events that can aggravate the flooding situation later in March over parts of the Ohio, Mississippi and Tennessee valleys," Vido said.

So while fluctuations in rainfall and magnitude of flooding are to be expected over part of the south-central United States moving forward into the spring, long-term relief from potential flooding is likely many weeks away.

Locally strong storms over lower Mississippi Valley expected

In terms of severe thunderstorms, the risk of an outbreak is low at this time with the midweek storm.

However, there is the potential for severe thunderstorms at the local level in parts of the interstate 10 and 20 corridors over the lower Mississippi Valley from later Tuesday to Wednesday. Some of the storms in this zone may bring strong wind gusts and flash flooding. A brief spin-up tornado cannot be ruled out.

A larger area of thunderstorms, which may become severe, is possible over the lower Mississippi, Tennessee and lower Ohio valleys this weekend.