Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
542 ACUS02 KWNS 300555 SWODY2 SPC AC 300553 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1253 AM CDT Sun Aug 30 2026 Valid 311200Z - 011200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE CENTRAL PLAINS INTO THE MIDWEST... ...SUMMARY... Sparse severe thunderstorms, accompanied by wind and hail, are possible tomorrow (Monday) from the central Plains toward parts of the Midwest. ...Synopsis... An upper ridge will remain in place over the central and eastern CONUS tomorrow (Sunday), with at least one low-amplitude mid-level trough and several other smaller-scale impulses poised to pivot around the upper ridge, overspreading the central High Plains to the Northeast in the process. Given the presence of these impulses atop a moist boundary layer, at least isolated thunderstorms are expected all along the northern periphery of the ridge. While thunderstorms will be more sparse over parts of the central Plains to the Midwest, cooler temperatures and stronger flow aloft overspreading the aforementioned moist boundary layer will foster enough buoyancy and shear to support a conditional severe threat. ...Central Plains to the Midwest... A low-amplitude mid-level trough will traverse the Upper MS Valley while a smaller mid-level impulse impinges on the central High Plains after dark. As such, upper support will be limited along an effective warm frontal boundary extending from central NE to far western WI during the day. Along this boundary, surface dewpoints should exceed 70 F as 7.5-8 C/km mid-level lapse rates are advected overhead from the west, yielding 2000-3000 J/kg MLCAPE. Furthermore, modest westerly mid-level flow will also contribute to 35-40 kts of effective bulk shear, which is more than adequate for multicells and supercells should a storm develop and mature. Severe wind and hail would be the main threats with such a storm. Despite the favorable kinematic and thermodynamic parameter space, the severe threat remains quite conditional given the lack of upper support, as suggested by CAMS, which show little in the way of storm coverage. Given doubts on more than sparse storm coverage, only Marginal Risk probabilities remain in place. ..Squitieri.. 08/30/2026 $$