Day 1 Convective Outlook
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Issued: · Valid: –
Summary
Isolated to scattered severe thunderstorms capable of producing large hail and damaging wind gusts may occur across parts of the central and southern Plains into the Ozarks this afternoon and evening. The Upper Ohio Valley may also see occasional damaging winds from thunderstorms developing this afternoon.
Product Text
000 ACUS01 KWNS 121250 SWODY1 SPC AC 121248 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0748 AM CDT Sat Sep 12 2026 Valid 121300Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL/SOUTHERN PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms capable of producing large to very large hail and severe/damaging winds may occur across parts of the central/southern Plains into the Ozarks this afternoon and evening. ...Central/Southern Plains into the Ozarks... Mainly elevated thunderstorms have persisted overnight into the early morning across southern NE into eastern KS/western MO, aided by a modest low-level jet. This activity will probably tend to weaken through the remainder of the morning, but some recent guidance suggests additional thunderstorms developing along its outflow across southern KS/northern OK over the next few hours. If this development occurs, it would potentially complicate destabilization and severe potential later today. Recent surface observations also show a fairly strong cold front draped from eastern CO into KS and northwest MO. This boundary will likely serve as a focus for robust thunderstorm development this afternoon/evening as well. With a rather moist low-level airmass forecast to be present along/south of the front, current expectations are for a narrow zone of moderate to strong instability (MLCAPE 2000-3500 J/kg) to develop this afternoon from the eastern OK/TX Panhandles into southern KS/northern OK. Weak low-level winds will veer to west-northwesterly and strengthen some with height through mid/upper levels, supporting around 30-40 kt of deep-layer shear and updraft organization. While large-scale ascent will remain fairly weak/nebulous across the southern/central Plains, most guidance shows at least isolated robust thunderstorm development along the front by 21-23Z as convective temperatures are reached. While there is still uncertainty regarding convective evolution and persistence of ongoing thunderstorms this morning, some signal exists in most recent short-term guidance that isolated to scattered convection will form along much of the length of the front later today in a rather favorable environment to support severe thunderstorms. Any sustained supercells would pose a threat for large to very large hail, with steep mid-level lapse rates and ample instability in the hail-growth zone supporting potential for 2+ inch diameter hail on an isolated basis. Somewhat higher-based convection also appears probable from the eastern OK/TX Panhandles into parts of southwest/south-central KS and northern OK, where a very well-mixed boundary layer with steep low/mid-level lapse rates should promote an environment that supports scattered severe downdraft winds. Some gusts could exceed 75 mph. The potential for clustering this afternoon and evening remains unclear, but some chance for at least isolated severe/damaging winds may persist into much of OK and the Ozarks, dependent on upstream convective evolution in KS/western MO. ...Upper Ohio Valley... A narrow corridor of filtered diurnal heating and related moderate instability should develop across parts of the upper OH Valley this afternoon between denser clouds and precipitation occurring across OH, and a stationary boundary to the east. Thunderstorms will gradually increase in coverage and intensity through the afternoon, aided by forcing for ascent associated with an approaching weak mid-level shortwave trough. While mid-level lapse rates will remain poor, sufficient deep-layer shear coupled with modest steepening of low-level lapse rates suggest some risk for occasional damaging winds with any loosely organized clusters/line segments that can form. ..Gleason/Lyons.. 09/12/2026 $$