Tornado watch issued in four US states as National Weather Service warns 'be prepared'

A severe storm is ripping through parts of the US, prompting officials to issue tornado watches in four central states Wednesday morning.

The National Weather Service (NWS) issued tornado watches for parts of Oklahoma, Kansas, Arkansas and Missouri starting as early as 5:20AM CT, warning residents to 'be prepared.' 

A tornado warning has been issued in Kansas City, Missouri, and will remain in effect until 7:30am CT.

A Tornado Warning indicates that tornado is imminent, and residents of the affected area should seek safe shelter immediately,' the NWS states. 

'TAKE COVER NOW!' agency officials wrote in the Kansas City alert. 'Move to a basement or an interior room on the lowest floor of a sturdy building. 

'Avoid windows. If you are outdoors, in a mobile home, or in a vehicle, move to the closest substantial shelter and protect yourself from flying debris.' 

This is just the beginning of the 'life-threatening' impact this powerful spring storm will have on the central US, the NWS warned, adding that this is likely to be a 'multi-day catastrophic and potentially historic event.' 

The storm will trek eastward through the Midwest, Mississippi Valley, and southern Plains today, spreading 'widespread, intense' thunderstorms from the Great Lakes to the Gulf Coast. 

The NWS Storm Prediction Center has classified this severe weather outbreak as a 'High Risk' (level five out of five) across south-central where tornado watches and warnings have been issued.

Very large hail and 'significant' damaging winds are also expected in these states.

The rest of the Mid-South is also facing a 'severe threat' today. These areas can expect to see a 'more scattered but still significant threat of tornadoes, large hail, and damaging winds,' the NWS stated. 

'Unfortunately, this severe threat will be compounded by the beginning of a life-threatening flash flood event,' the agency added. 

For today, flood watches have been issued parts of 9 states: Tennessee, West Virginia, Kentucky, Illinois, Louisiana, Indiana, Pennsylvania, Arkansas and Ohio. 

These alters will remain in effect through Sunday, and by Thursday, watches will extend to parts of three more states: Missouri, Michigan and Wisconsin. 

The risk of flash flooding will be 'particularly dangerous' in areas near Paducah, Kentucky;  Little Rock, Arkansas and Memphis, Tennessee as multiple rounds of heavy rain batter these cities. 

As the torrential downpours persist through the weekend, more than 46 million people across the central US will be impacted, and at least 13 million will be within a high- to extreme-flood risk zone, Accuweather reported. 

'More than a foot of rain may pour down from portions of Arkansas to Kentucky and Ohio, likely triggering rapid, major and historic flooding,' Accuweather meteorologists warn.

The rains will result from an atmospheric river, or a massive band of water vapor in the atmosphere, originating from the Caribbean, according to AccuWeather senior storm warning meteorologist William Clark.

'Tropical moisture raises the risk of excessive rainfall,' he said. 

The barrage of severe weather should reach peak intensity today, Accuweather predicted.

But the storm will continue to rage Thursday, with a severe weather zone stretching from parts of central Texas nearly to the mid-Atlantic coast.

Rounds of severe weather will persist through Friday and Saturday, centered over the lower Mississippi Valley, Accuweather reported.