ACUS02 KWNS 080528 SWODY2 SPC AC 080527 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 AM CDT Wed Jul 08 2026 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THURSDAY INTO THURSDAY NIGHT ACROSS PARTS OF THE CENTRAL GREAT PLAINS AND ACROSS PARTS OF THE LOWER MISSOURI VALLEY INTO LOWER OHIO VALLEY... ...SUMMARY... Scattered strong thunderstorm development, potentially including a few evolving clusters, may impact portions of the central Great Plains and lower Missouri Valley through lower Ohio Valley Thursday through Thursday night, posing a risk for severe wind gusts and some hail. ...Discussion... Modest mid-latitude westerlies likely will remain centered near the Canadian/U.S border through this period. In the wake of one short wave trough slowly continuing to pivot northward into the Northwest Territories, and ahead of another digging near the British Columbia coast, broad mid-level ridging is forecast to build across the central Canadian/U.S. border vicinity Thursday through Thursday night. Downstream, to the south of a perturbation digging southeast of Hudson/James Bays, broad mid-level troughing is forecast to overspread the lower Great Lakes through northern Atlantic Seaboard. In lower latitudes, a number of more subtle perturbations are forecast to progress through generally weak zonal flow, around the northern periphery of mid-level ridging centered in the subtropics. However, there remains a notable signal within model output that at least a couple of these may be amplified by developing convection, accompanied by belts of strengthening flow which could promote organizing convection capable of producing swaths of strong to severe wind gusts. While the most substantive thunderstorm development through this period appears likely to focus east of the Front Range into portions of the lower Missouri Valley through Ohio Valley, as well as across parts of the northern Mid Atlantic, more widely scattered strong to severe thunderstorm development appears possible closer to the mid-latitude westerlies. This may focus along a weak surface front advancing slowly southward across parts of the lower Great Lakes through northern New England, and within lee surface troughing across parts of the northern Great Plains. ...Lower Missouri/Ohio Valleys... Most guidance continues to indicate the generation of one or two notable mesoscale convective vortices and associated jet streaks, at least initially emanating from convection developing across the central Great Plains Wednesday night. The NAM continues to forecast the strongest convective perturbation, though the 08/00Z run now suggests that this will occur with convection overspreading east central Missouri into southern Illinois late Thursday night. Otherwise, a consensus of guidance generally suggests the development of strengthening westerly mid-level flow (on the order of 30-50 kt around 700 mb) in a belt across the lower Missouri Valley during the day, before slowly shifting toward the lower Ohio Valley through Thursday night. Based on latest model output, strongest renewed thunderstorm development seems most probable within forcing for ascent associated with strengthening low-level warm advection, along an outflow boundary trailing the initial MCV. Aided by inflow of seasonably high boundary-layer moisture content (including surface dew points in the 70s) supportive of CAPE on the order of 2000+ J/kg, vertical shear may become supportive of a sustained organized convective system with potential to produce strong to severe wind gusts by Thursday evening into Thursday night, if not earlier. ...Front Range into central Great Plains... Latest model output continues to indicate that moistening southeasterly low-level flow across the high plains will destabilize sufficiently by late afternoon to support intensifying thunderstorm development off the Front Range. Aided by shear due to pronounced veering of winds with height from the surface to mid-levels, this may include widely scattered supercells initially. Aided by forcing for ascent downstream of an approaching mid-level perturbation, convection-allowing guidance suggests that storms will subsequently increase in number across the high plains, with consolidating cold pools supporting further upscale growth and eastward propagation. Forcing for ascent near the nose of a strengthening nocturnal southerly low-level jet may contribute to maintenance of a cluster with potential to produce strong to severe gusts into late evening/overnight across the southwestern Kansas vicinity. ...Mid Atlantic... Destabilization within lee surface troughing may become sufficient to support thunderstorm development with potential to produce strong wind gusts and grow upscale Thursday afternoon into evening, aided by forcing for ascent and modest strengthening of mid-level flow, associated with a remnant short wave impulse emerging from the Tennessee Valley. ...Southeastern Arizona... Convection-allowing and related guidance suggests that thunderstorm development is probable Thursday afternoon across parts of the Mogollon Rim into higher terrain of southwestern New Mexico, and perhaps southeastern Arizona, around the eastern periphery of a weakening mid-level ridge. Aided by light northeasterly steering flow off the mountains, into a hot and deeply mixed boundary layer with at least weak CAPE, a few strong downbursts appear possible, with potential for upscale growth on consolidating cold pools to generate a broader strong to severe wind gust threat into Thursday evening. ..Kerr.. 07/08/2026 $$