Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
637 ACUS02 KWNS 160528 SWODY2 SPC AC 160526 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1226 AM CDT Sun Aug 16 2026 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NEBRASKA AND THE MID-MISSOURI VALLEY...AND ACROSS THE SOUTH-CENTRAL APPALACHIANS... ...SUMMARY... Strong to severe thunderstorms are possible Monday afternoon and evening across portions of the northern and central Plains, and parts of the southern Appalachians/Carolinas. ...Northern/Central Plains... An upper shortwave trough will deepen as it develop east/southeast across Ontario and the Upper Midwest, resulting in broader height falls from the northern/central Plains to Great Lakes. As this occurs, 40-50 kt northwesterly flow aloft will overspread the region. At the surface, a cold front will extend from northwest MN into western NE by 00z. Ahead of the front, a corridor of 60s F dewpoints are expected across central/eastern NE into IA/southeast SD and MN. Isolated to scattered thunderstorms are likely to develop by late afternoon ahead of the surface boundary. Modestly steep lapse rates and strong heating of the moist boundary layer will result in 2500-3500 J/kg MLCAPE amid 35+ kt effective shear magnitudes. This should result in organized supercells structures capable of large hail and damaging gusts. There is some potential upscale growth could occur during the evening across NE as a modest low-level jet develops. If this occurs, the damaging wind risk could increase. ...South-central Appalachians... A vorticity max located over the Lower OH Valley will develop east/southeast through 30-40 kt west/northwesterly flow aloft Monday afternoon and evening. A very moist and unstable airmass will be in place amid strong daytime heating. Large-scale ascent will increase as the vorticity maxima approaches during the afternoon, and a surface boundary begins to sag south/southeast over the region. Steep low-level lapse rates, high PW values, and 25-30 kt effective shear magnitudes could result in organized clusters producing damaging gusts through evening. ..Leitman.. 08/16/2026 $$