Severe weather outlook: Marginal risk of severe thunderstorms across FL, IL, IN, KY

SPC AC 111630 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1030 AM CST Wed Nov 11 2026 Valid 111630Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE LOWER OHIO AND WESTERN TENNESSEE VALLEYS...AS WELL AS ACROSS THE EAST-CENTRAL FLORIDA PENINSULA... ...SUMMARY... Thunderstorms capable of producing isolated hail, damaging winds, and perhaps a tornado may occur this afternoon and evening across parts of eastern Illinois into Indiana, western/central Kentucky, and middle Tennessee. Isolated severe thunderstorms are also possible across the east-central Florida Peninsula. ...Midwest/Lower Ohio Valley into Middle Tennessee... Recent satellite imagery shows a lead shortwave trough moving into northern IL, with another shortwave trough farther back northwest moving into the Mid MO Valley. Showers and thunderstorms are ongoing near the lead shortwave. Thunderstorm intensity has decreased over the last half hour or so as these storms move into an environment with less elevated buoyancy (as observed by the 12Z ILX sounding). The lead shortwave is forecast to continue eastward into the OH Valley while the second shortwave continues more southeastward into the Lower OH Valley vicinity. The surface low currently over the IA/IL border vicinity is forecast to progress eastward with the lead wave while an attendant cold front sweeps southeastward through the mid MS Valley/Mid-South, and lower OH Valley this afternoon and evening. Increasing low-level moisture is anticipated ahead of this front, advecting northeastward into the region from the Ozarks/Mid-South region. Recent surface analysis shows the mid 50s dewpoints are still in northern AR, so there is some question as to how far northeastward the greater low-level moisture will reach before frontal passage. Current expectation is for the best overlap between low-level moisture (and associated buoyancy) with the stronger large-scale ascent will occur across southern IN and adjacent western KY. Here, the combination of weak buoyancy (i.e. MLCAPE around 500-800 J/kg) and 30-40 kt of deep-layer shear oriented largely orthogonal to the surface cold front should support a mix of bowing clusters and supercells. Isolated hail and damaging gusts will be the primary risks. Hail is more likely with any more cellular activity and damaging gusts more likely with any fast-moving bowing segments. Modestly enhanced low-level shear may also support a low-probability tornado risk, but a tendency for low-level flow to veer to westerly should reduce effective SRH with time through the late afternoon/evening. The isolated severe risk should diminish with eastward extent this evening across the lower OH Valley as front outruns the low-level moisture and daytime heating wanes. ...Central/Southern Florida Peninsula... Isolated to scattered thunderstorms are expected across the central/southern FL Peninsula this afternoon. Glancing large-scale ascent associated with a weak mid-level perturbation over the Southeast should aid this convective development. A warm layer around 700 mb could limit overall buoyancy, but 500 mb temperatures will be around -9 to -11 deg C and most forecast sounding still show 1500+ J/kg of uninhibited MLCAPE this afternoon. Moderate deep-layer shear will exists across the region as well. These conditions appear supportive of marginally severe hail and gusty winds within the stronger cores, which appear most probable along the east-central FL Coast. ..Mosier/Halbert-K.. 11/11/2026 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z