Millions in path of 'extreme' life-threatening floods as Arthur slams EIGHT states after making landfall

As many as 40 million people across eight states are in the deadly path of Tropical Storm Arthur after the first named storm of hurricane season made landfall Wednesday night.

Arthur, which has been downgraded to a post-tropical cyclone on Thursday, slammed into the Texas Coast last night, and is now projected to barrel across the South, bringing severe flooding from Louisiana to the Carolinas.

Meteorologists with AccuWeather warned that Louisiana, Mississippi, Alabama and the Florida Panhandle will see 'extreme' levels of flooding along the coast and in urban areas throughout Thursday, with as much as 12 inches of rain falling.

Georgia and the Carolinas are expected to be impacted on Friday, as forecasters say Arthur will continue to bring 'life-threatening flooding, property damage and disruptions to commerce and travel.'

AccuWeather Hurricane Expert Alex DaSilva warned in a statement: 'Rainfall rates can reach 2-4 inches per hour, which can cause flooding to occur quickly and result in road closures, especially in urban areas.'

However, flooding is not the only concern tied to Arthur, as the National Weather Service has also issued a widespread tornado watch across coastal areas in Louisiana, Mississippi, Alabama and the Florida Panhandle.

In Mississippi specifically, weather officials upgraded that alert to an official tornado warning in Perry, Greene, Stone, Harrison, Hancock and Pearl River Counties - warning that twisters could touch down at any moment.

NWS said in a statement: 'TAKE COVER NOW! 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 a breaking story. More details to follow.