A widespread severe weather outbreak is taking shape across a large swath of the central United States this evening, stretching from Texas and Louisiana north through Illinois and Indiana. Nearly forty million people are at risk for damaging winds, large hail, and possibly a few tornadoes.
While spring is the most active season for severe weather in the United States, the country experiences a second, less intense peak in severe weather during the fall months as air masses duke it out (to use a technical term). A powerful cold front is marching out of the Plains towards the Mississippi River Valley this evening, with strong to severe thunderstorms firing up along and ahead of the leading edge of the front. This same cold front will bring the first real blast of cold air (30s are possible as far south as central Alabama on Sunday morning).
As of the publication of this post, severe thunderstorm watches are in effect from central Texas to central Illinois ahead of the storms. The main risks with these storms include wind gusts to 70 MPH (especially in line segments that develop), very large hail on the order of 1.50" to 2.00" in diameter (likely in discrete storms), and the possibility for a tornado or two in discrete storms that are able to tap into areas of low-level shear.
The most widespread risk from today's storms is expected to be damaging winds. The SPC has issued a 30% risk for damaging winds (map above) across the entire state of Arkansas and large parts of Texas, Oklahoma, and Missouri. The SPC's website lists almost 11 million people under the 30% risk, including larger cities such as Memphis, Shreveport, and Little Rock.
Keep an eye on watches issued by the Storm Prediction Center and warnings issued by your local National Weather Service office this evening and tonight. Make sure you have a way to be alerted for severe weather if you're asleep. Most smartphones have Wireless Emergency Alert capability now, which automatically sounds that annoying Emergency Alert System tone when your location goes under a flash flood warning or tornado warning.
[maps by the author]