Day 1 Convective Outlook
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Issued: · Valid: –
Summary
Isolated to scattered severe thunderstorms capable of producing large hail and damaging winds may occur across parts of the south-central Plains into the Ozarks this afternoon and evening.
Product Text
000 ACUS01 KWNS 121637 SWODY1 SPC AC 121635 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1135 AM CDT Sat Sep 12 2026 Valid 121630Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTH-CENTRAL 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 south-central Plains into the Ozarks this afternoon and evening. ...Central/Southern Plains to the Ozarks... Scattered mainly elevated thunderstorms continue at midday across the region, including the strongest/occasionally-severe storms across southeast Nebraska into northeast Kansas that are occurring near/just behind a southeastward-moving cold front. Some severe hail will remain possible as these storms continue southeastward on the edge of the primary instability reservoir. This front, augmented by early day outflows, will otherwise serve as a focus for more 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 Oklahoma/Texas Panhandles across southern Kansas and northern Oklahoma. 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. 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 is expected from the eastern Oklahoma/Texas Panhandles into southwest/south-central Kansas and northern Oklahoma, where a very well-mixed boundary layer with steep low/mid-level lapse rates will promote an environment that supports severe-caliber downdraft winds. Some gusts could exceed 75 mph. A degree of storm clustering could occur into this evening. ...Upper Ohio Valley... A regional pocket of relatively cloud-free skies at midday will contribute to filtered diurnal heating and moderate instability across the region. Thunderstorms will further 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 develop. ..Guyer/Wendt.. 09/12/2026 $$