(CNN) — The severe storm threat it has expanded to more than 40 million people in the United States, according to the 2 am update from the Storm Prediction Center (SPC).
The threat now extends from southeast Texas east to Georgia and north to central Indiana and Illinois and includes Houston, New Orleans, Louisville, Birmingham, Nashville, Baton Rouge, Shreveport, Little Rock, Memphis, Nashville , St. Louis, Cincinnati and Louisville.
The Storm Prediction Center has issued a moderate risk advisory (level 4 of 5) of a severe storm threat for Tuesday afternoon and evening. The moderate area includes more than 1 million people in parts of east-central Louisiana and central Mississippi, including Jackson.
A higher risk (level 3 of 5) of severe thunderstorms surrounds the moderate risk and can still bring strong tornadoes, strong gusts of wind, and hail. This area includes Memphis, TN and Monroe and Alexandria.
In addition to potentially significant tornadoes, very large hail is possible in these storms. The storms are expected to begin late Tuesday afternoon and continue through the night and into the early morning.
“Severe thunderstorms capable of producing tornadoes, very large hail, and a few severe wind gusts this afternoon into the overnight period in parts of the lower and middle Mississippi Valley and parts of the Southeast. A few strong tornadoes will be possible.” warned the Spc Tuesday morning.
“Particularly Dangerous Situation” in the Lower Mississippi Valley
The Storm Prediction Center (SPC) has issued a tornado watch through 7 p.m. CST for northern and central Louisiana, central Mississippi, and southeast Arkansas. The alert was designated a “Particularly Dangerous Situation (PDS)” by Spc. This designation is reserved for the most significant severe storm threats and is only used in about 3% of watches.
“The parameters appear favorable for strong, long-track tornadoes to develop this afternoon and early evening,” the SPC said on the watch.
In addition to “numerous tornadoes and some intense tornadoes,” hail up to 2 inches in diameter and damaging winds of up to 75 mph are also possible.
The alert covers nearly 2.5 million people and includes Jackson, Mississippi and Alexandria, Louisiana.