Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1148 PM CST Fri Nov 28 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF EAST/SOUTHEAST TEXAS INTO LOUISIANA... ...SUMMARY... Isolated severe thunderstorms are possible across portions of east and southeast Texas into western Louisiana today and tonight. ...Synopsis... A broad upper trough and increasingly strong westerly flow over the central US are forecast to quickly intensify today, moving into the Ohio Valley by tonight. Accompanying the strengthening trough, a surface low over OK will deepen and shift toward the mid MS valley. Trailing the low, a strong cold front will sweep southeastward with increasing moisture ahead of it over the far southern Plains. Ahead of the front, isolated strong to severe storms are possible over parts of East TX and western LA this afternoon into early Sunday morning. ...Eastern Texas into western LA... South of the surface low across parts of central and southeast TX, low-level warm air advection is expected much of the day associated with a weakening 850 mb low-level jet. Persistent southerly flow will help transport low to mid 60s F dewpoints northward across the TX coastal plain into portions of central TX and far western LA. Filtered diurnal heating should allow for some warming of the relatively cool boundary layer. This warming, along with the increase in low-level moisture, should support at least weak destabilization by peak heating as cold mid-level temperatures from the approaching trough move overhead. While overall forcing and flow aloft should be modest south of the primary upper trough, isolated thunderstorms are possible within the warm advection regime through the afternoon and into the evening/overnight hours. Veering hodographs and a subtle increase in deep-layer shear should favor some storm organization with convection across southeast TX into far western LA. Wind fields will be weak, but slightly enlarged low-level hodographs (ESRH 100-200 m2/s2) and a cellular storm mode could favor transient supercell structures along with occasionally organized multicells. A brief tornado and marginally severe hail are possible with the stronger updrafts. While any sustained severe risk is likely to be contingent upon sufficient warming for surface-base buoyancy, at least a low-end risk is possible from late afternoon through much of the overnight hours ahead of the cold front. As the cold front moves south from the Red River into central TX this afternoon and into the evening, additional storms are likely to form along and behind it as the front encounters the northern fringes of the moisture plume. Despite sufficient buoyancy (MLCAPE 500-1000 J/kg), the undercutting nature of the surging front should tend to limit storm intensity. Still, sufficient deep-layer shear (35-45 kt) could support a few stronger clusters as a broken line develops and surges south. Isolated hail, and perhaps some strong gusts are possible as the front is expected to quickly move toward the coast and reach the Gulf early Sunday morning. ..Lyons/Weinman.. 11/29/2025Read more