SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0130 PM CST Fri Dec 26 2025 Valid 281200Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE MID MISSISSIPPI AND OHIO VALLEYS... ...SUMMARY... Isolated severe thunderstorms are possible Sunday into Sunday night from the Southern Great Lakes into parts of the Ohio and Mid Mississippi Valleys. ...Mid MS to the OH Valleys... An initially broad and multi-faceted positive-tilt upper trough over the central US is forecast to undergo substantial amplification as it moves eastward toward the Great Lakes Sunday and Sunday night. The corresponding surface low will quickly intensify as it moves eastward from KS/MO across northern IL. A trailing cold front will also strengthen, with low-level moisture transport ahead of the front (50s and 60s F surface dewpoints) aiding in modest destabilization Sunday evening. Elevated convection is likely to be ongoing over the MO valley vicinity early in the period associated with the strong low-level theta-E advection. This convection may remain elevated for much of the day as it tracks along a stalled frontal zone from northern MO/IL vicinity eastward into OH/IN and southern lower MI. Still, some elements may eventually become near-surface based with weak MUCAPE (100-200 J/kg) potentially supporting a few stronger gusts near the surface. Additional surface-based storms will likely develop within the moistening warm sector over the northern Ozarks and mid MS valley late Sunday afternoon. A low-topped convective band could organize along the front as it moves east/southeast from the MS/OH Valleys toward the northern Gulf Coast. As the trough and surface low deepen, flow aloft will also increase. A strong (45-55+ kt) low-level jet will develop from the Mid South to the southern Great Lakes, rapidly strengthening low and mid-level shear profiles. While buoyancy will be marginal (250-500 J/kg MUCAPE), this should be sufficient for stronger linear segments to organize along the surging cold front. Isolated damaging gusts and perhaps a brief tornado or two are possible as the line moves quickly eastward over the Mid MS and eventually the OH Valley Sunday night. ..Lyons.. 12/26/2025
