12AM Day 2 Convective Outlook for Sunday, October 19. 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.