SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CDT Sat Oct 18 2025 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF THE OHIO VALLEY TO THE APPALACHIANS AND MID ATLANTIC AS WELL AS THE GULF COAST... ...SUMMARY... Isolated wind damage may occur on Sunday into Sunday evening from parts of the Ohio Valley toward the Appalachians and Mid Atlantic regions. Additional isolated severe storms are possible over the Gulf Coast early Sunday. ...OH Valley into the Appalachians and Mid Atlantic... A broad but strong upper trough over the central US early Sunday is forecast to continue intensifying as it moves quickly eastward into the eastern Great Lakes and Northeast. Ascent from the trough and a 90+ kt mid-level jet streak will deepen a surface low over Lower MI, forecast to move north/northeastward into southern Canada during the day. Trailing the low, a cold front over central OH and into KY and TN will race eastward into the Appalachians and Mid Atlantic by Sunday evening. Shallow convection is likely to be ongoing ahead of the front from eastern MI into OH/KY at the start of the forecast period. Cloud cover and weak low-level moisture advection (50s F dewpoints) will support very weak destabilization ahead of the cold front. Still, the strong ascent (12 hr H5 GPH change of -180 to -200m) will help force a shallow convective band along the cold front as it moves eastward. While little to no lightning is expected, strong low and mid-level winds across much of the northeastern CONUS may allow for isolated damaging gusts with this low-topped convection. ...Gulf Coast.. Farther south, scattered storms should be ongoing at 12z along the front over southern AL/MS and LA. Low 70s F dewpoints should support around 1000 J/kg of SBCAPE amidst moderately strong veering wind profiles. This will support some storm organization of short line segments or transient supercells. Damaging gusts and perhaps a tornado or two are possible before storms move offshore by midday. Subsidence on the southern edge of the upper trough will then overspread the remnant moist and weakly unstable air mass over eastern AL into GA and the southern Appalachians Sunday afternoon. While isolated storms will remain possible along the cold front where weak buoyancy can develop, most guidance shows convection weakening through the remainder of Sunday. ..Lyons.. 10/18/2025
