Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
316 ACUS02 KWNS 121730 SWODY2 SPC AC 121728 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Fri Jun 12 2026 Valid 131200Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SATURDAY AFTERNOON INTO SATURDAY NIGHT ACROSS EASTERN KANSAS...ADJACENT PORTIONS OF SOUTHEASTERN NEBRASKA AND NORTHEASTERN OKLAHOMA...AND MUCH OF WESTERN THROUGH CENTRAL MISSOURI... ...SUMMARY... One or two evolving thunderstorm clusters appear possible across parts of the central Great Plains and lower Missouri Valley vicinity Saturday afternoon through Saturday night. Some of this activity will pose a risk for producing large hail and swaths of strong, potentially damaging wind gusts. ...Discussion... Downstream of amplified mid-level ridging, offshore of the U.S. Pacific coast through British Columbia, it appears that flow will begin to veer to an increasing northwesterly component across and east of the Rockies through this period. Within this regime, substantive mid-level troughing is forecast to dig across the Upper Midwest, to the southwest of a lingering mid-level low centered across northwestern Ontario. Spread within model output remains larger concerning short wave perturbations digging through initially weaker flow across the Missouri through lower Ohio Valleys, and the extent to which they may begin to suppress the northern periphery of subtropical ridging centered over the northern Gulf Basin. In lower levels, an initial, convective outflow enhanced, surface front overspreading much of the Mid Atlantic through Mid South vicinity will likely already be in the process of weakening at the outset of the period. However, surges of cooler/drier air will continue to develop southward into and through the interior of the U.S., with the general leading edge reaching the lower Great Lakes through Ohio Valley, Ozarks Plateau and Texas South Plains by 12Z Sunday. This may be preceded across the Ohio Valley through western slopes of the Appalachians by outflow from extensive prior convective development. ...Central Great Plains into Missouri Valley... The potential for increasing thunderstorm development at the outset of the period across eastern Nebraska into western Iowa (near the nose of an east-northeastward advecting plume of elevated mixed-layer air) coupled with potential for substantive, but weakening, remnant convection from overnight overspreading the Ozark Plateau, contribute to continuing uncertainty concerning subsequent convective development Saturday through Saturday night. The evolution of convective outflows, and their impact on boundary-layer destabilization, coupled with uncertain short wave developments, will substantially impact the timing, location and potential upscale growth of potentially stronger thunderstorm development. However, beneath the plume of elevated mixed-layer air, a corridor of stronger boundary-layer heating and deeper mixing across Kansas during the day seems to provide the highest certainty for moderate to strong destabilization. Near the nose of this regime, somewhere across eastern Kansas into western Missouri, based on a consensus of model output, low-level warm advection in the presence of weaker inhibition may provide the focus for intensifying thunderstorm development by late afternoon. And there appears a general signal in the model output that a modifying outflow boundary/zone of differential heating may provide a focus for the southeastward development of upscale growing convection toward the Mid South through Saturday night. As this occurs, increasing thunderstorm development also appears probable ahead of the southward advancing cold front across Kansas through Oklahoma and the Texas Panhandle vicinity. Although deep-layer shear may be initially modest, it may still be sufficient to support the evolution of a few supercells capable of producing large hail and potential for a couple tornadoes, before evolving swaths of strong to severe wind gusts become the more prominent threat with organizing clusters into late Saturday evening. ..Kerr.. 06/12/2026 $$