A massive storm is set to bring life-threatening tornadoes and potentially historic floods in what could be the worst 24 hours of extreme weather this year.

The National Weather Service (NWS) warn that over 15 states are in the path of this major storm which is bringing intense rainfall to millions of people from the Gulf Coast to the Northeast.

The storm watches now include Pennsylvania, Ohio, Indiana, Kentucky, Tennessee, Illinois, Arkansas, West Virginia, and portions of Louisiana, Maryland, Michigan, Mississippi, Missouri, Oklahoma, and Texas.

More than a foot of rain will accumulate in some areas between Wednesday and Saturday. There could be well over 18 inches of rainfall in parts of Arkansas, Missouri, Tennessee, and Kentucky, AccuWeather warned.

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. 

AccuWeather senior storm warning meteorologist William Clark warned that this storm could bring four to five months’ worth of rain to a 1,000-mile-long swath of the country in just four days.

The worst of this historic flood event is expected to submerge portions of Arkansas, Missouri, Missouri, Illinois, Kentucky, and Indiana starting Wednesday night.

AccuWeather warned that there could be well over 18 inches of rainfall in parts of Arkansas, Missouri, Tennessee, and Kentucky this week

Meteorologists with the National Weather Service warn that at least 12 states in the South and Midwest are already under a severe flood watch (Stock)

Meteorologists warn that this week’s storm could bring the equivalent of 4 to 5 months of rain to the South and Midwest in just 4 or 5 day (Stock)

AccuWeather chief meteorologist Jonathan Porter warned: ‘Dangerous situations can escalate to life-threatening emergencies in a matter of seconds with a flash flooding threat as serious as this.’

‘Should the amount of rain occur that we anticipate over the middle of the nation, it would exceed the 500 to 1,000-year average,’ Clark added. ‘Truly, the potential is there for a historic flash flooding event.’

At least 10 states, from Texas to Michigan, face a moderate to high chance of deadly twisters forming tonight.

AccuWeather says the high tornado risk zone includes parts of Indiana, Illinois, Kentucky, Tennessee, Missouri, Arkansas, and northern Louisiana. 

Tornado watches already started going out Wednesday morning in parts of Oklahoma, Kansas, Arkansas, and Missouri, urging residents to ‘be prepared.’ 

‘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 newest tornado threat comes less than three weeks after a ‘mega storm’ ripped through this same part of the US in March.

Over 40 people died due to the extreme weather event, which dropped more than 70 tornadoes on communities throughout the South and Midwest.

However, that storm did not come close to delivering the amount of rain and potential for historic flooding meteorologists are warning this new storm could bring.

Meteorologists say Wednesday’s downpour could break 500 and 1,000-year rainfall averages, turning this into a historic and deadly flood event

The severe storm started ripping through parts of the US, sparking a tornado watch in four states Wednesday morning

‘Parts of Kentucky, Tennessee, Missouri, and Arkansas could see one to nearly two feet of rainfall by the end of the weekend,’ Porter added.

‘This is essentially an atmospheric river setup that will pull tremendous amounts of moisture from the tropics into the central U.S.’

The AccuWeather team warns that the period from Wednesday morning through Wednesday night will likely carry the greatest threat of extreme weather the US has seen so far this year.

It’s already been a chaotic first three months of 2025, with waves of winter storms, tornadoes, and floods pummeling most of the country.

In February, a ‘polar vortex collapse’ left a mess across much of the US, bringing feet of snow, landslides, and cancelled flights to millions of Americans.

A ‘polar vortex collapse’ basically means the big, cold swirl of air that constantly spins tightly around the North Pole begins to wobble or break apart, letting frigid Arctic air spill down into places like the US or Europe.

Meteorologists noted that the jet stream bringing cold air from the north was locked in an almost perfectly straight line over America, moving from west to east that entire month.

This nonstop weather system continued to fuel winter storms, which developed in the Plains and Midwest and swept up into the Northeast and New England.

Things didn’t get any better in March, as another polar vortex collapse in the middle of the month had forecasters predicting a late start to spring.

Forecasters say several areas face a high likelihood of seeing a tornado develop on Wednesday, including Arkansas, Tennessee, and Kentucky

Recent floods in Texas brought rainfall totals that exceeded records that go back over 100 years, killing at least 3 people on March 27

On March 14, the weekend mega storm demolished communities throughout the South, from Oklahoma to Missouri to Mississippi.

Roughly a quarter-million people were left without power in Missouri, Georgia, North Carolina, Alabama, and Michigan on March 16 alone.

On March 27, at least three people were killed in Texas as floods overwhelmed roadways and forced many drivers to leave their cars behind.

Between six and 12 inches of rain fell in parts of South Texas over a 24-hour period, according to the National Weather Service.

This week’s downpour throughout the country could bring similarly deadly conditions, with the AccuWeather team projecting that intense rainfall will bring flooding risks as far south as Texas and Louisiana and as far north as Michigan and Pennsylvania.

Thunderstorms are expected to still be intense moving into Friday and Saturday, bringing more hail and wind gusts between 60 and 70 mph.

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.