SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1200 AM CST Fri Nov 07 2025 Valid 071200Z - 081200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO AND TENNESSEE VALLEYS... ...SUMMARY... Thunderstorms with isolated large hail and marginally severe wind gusts are possible today into this evening, across parts of the Ohio and Tennessee Valleys. A few marginally severe storms could also develop in the central Gulf Coast states from afternoon into the overnight period. ...Tennessee and Ohio Valleys/Central Gulf Coast States... A mid-level trough, and an associated cold front will move eastward through the mid Mississippi Valley today. Ahead of the front, an axis of low-level moisture will be in place, along which surface dewpoints will be in the upper 50s and lower 60s F. Destabilization along the moist axis is expected to be modest due to abundant cloud cover. However, MLCAPE could locally peak near 1000 J/kg by late afternoon from northern Mississippi into southern Kentucky. Thunderstorms are expected to form along and near the front during the mid afternoon, with the storms moving eastward toward the central Appalachians in the late afternoon and early evening. Along this southwest-to-northeast corridor of instability, forecasts soundings late this afternoon have moderate to strong deep-layer shear in the 50 to 60 knot range, with 700-500 mb lapse rates around 7 C/km. This could be enough for rotating storms capable of isolated large hail. The stronger cells could also produce marginally severe wind gusts. The area with the greatest severe threat is expected to be relatively small, mainly due to instability which is forecast to remain weak. Further south into parts of the central Gulf Coast, surface dewpoints in the lower to mid 60s F may be enough to allow moderate instability to develop by afternoon. Although large-scale ascent is forecast to remain weak, isolated storms could form along and to the east of a moist axis. Moderate deep-layer shear and steep low-level lapse rates could be sufficient for marginal severe threat. Hail and a few isolated severe gusts will be possible with the stronger cells. Due to the instability, which is forecast to remain in place as the trough moves into the Appalachians, a marginal severe threat could continue into the overnight period. ..Broyles/Supinie.. 11/07/2025
