Severe weather outlook: Marginal risk of severe thunderstorms across AL, AR, IL, IN

SPC AC 040037 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0637 PM CST Tue Nov 03 2026 Valid 040100Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE LOWER TO MID MISSISSIPPI VALLEY... ...SUMMARY... Thunderstorms with potential for isolated severe wind gusts and perhaps a brief tornado will be possible this evening and tonight across the lower to mid Mississippi Valley. ...Lower to Mid Mississippi Valley... The latest water vapor imagery shows an upper-level low in the mid Missouri Valley with a trough extending southward into the eastern part of the southern Plains. Cyclonic mid-level southwesterly flow is located ahead of the trough in the lower to mid Mississippi Valley. Within this flow, a broad band of precipitation is ongoing from central Illinois southward to Louisiana. Scattered thunderstorms are occurring on the southern end of the band. Ahead of this band, instability is generally weak except in the lower Mississippi Valley, where surface dewpoints in the 70s F are contributing to moderate instability. Although moderate deep-layer shear is present across much of the lower to mid Mississippi Valley, low-level lapse rates are very poor. In spite of this, strong low-level shear coupled with the instability could be enough for an isolated potential for severe wind gusts and perhaps a tornado. However, any severe threat will remain marginal this evening and tonight. ..Broyles.. 11/04/2026 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z