Day 2 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1245 PM CDT Fri Apr 03 2026 Valid 041200Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SATURDAY AFTERNOON AND EVENING ACROSS PARTS OF SOUTHEASTERN INDIANA...NORTHERN KENTUCKY...MUCH OF OHIO...SOUTHEASTERN LOWER MICHIGAN...WESTERN PENNSYLVANIA AND NEW YORK... CORRECTED FOR WORDING AND TYPOS ...SUMMARY... Severe thunderstorms may develop and overspread the lower Great Lakes vicinity and middle through upper Ohio Valley Saturday afternoon and evening, accompanied by strong to severe wind gusts and potential for a couple of tornadoes. ...Discussion... As mid-level ridging builds further across the British Columbia and Pacific Northwest vicinity Saturday through Saturday night, models indicate that several digging downstream short wave troughs across the Canadian Prairies into the northern U.S. Great Plains may contribute to the northeastward acceleration of a notable mid-level low, now slowly turning eastward toward the middle Missouri Valley. In response to these developments, an initially modest surface cyclone associated with the lead perturbation is generally forecast to undergo substantive deepening while occluding across and northeast of the upper Great Lakes vicinity. A secondary cyclone may form across the southeastern Michigan through Lake Huron/Georgian Bay/adjacent Ontario vicinity by Saturday afternoon, with a trailing cold front continuing to advance east of the Mississippi Valley and southward through the southern Great Plains, into the Appalachians/lower Mississippi Valley/northwest Gulf coast vicinity by early Sunday. Initially cold, stable air to the north of a preceding front may remain entrenched across much of New England through this period, while widespread thunderstorm development today through tonight cuts off the advection of elevated mixed-layer air and associated steeper mid-level lapse rates to the east of the Mississippi Valley. At the same time, the impact of lingering pre-frontal convective development, associated surface outflow and northeastward/eastward advecting remnant cloud cover on subsequent destabilization within a potentially expanding warm sector across the mid/upper Ohio Valley and lower Great Lakes region remains unclear. ...Ohio Valley into lower Great Lakes region... Conditionally, a relatively moist (60+ F surface dew points) air mass within the evolving warm sector is likely to become conducive to organized severe thunderstorm development, including supercells, Saturday afternoon and evening. However, stronger mid/upper support for ascent may remain displaced to the northwest of much of the destabilizing warm sector, with strongest forcing for convection confined to the front, or, perhaps more likely, a conglomerate pre-frontal outflow. Although the signal in model output is not particularly strong, it appears possible that convection may begin re-intensifying along the leading outflow boundary while overspreading southeastern Lower Michigan into the lower Ohio Valley by early afternoon. As this occurs, strong lower/mid-tropospheric shear beneath south to southwesterly wind fields strengthening to 40-60+ kt in the 850-500 mb layer will be more than sufficient to support organization and increasing risk for severe wind gusts and tornadoes. This threat likely will persist as activity overspreads much of the remainder of the Ohio Valley and lower Great Lakes region into Saturday evening. ...Parts of the Mid South into northwestern Gulf Coast... Weaker mid/upper forcing for ascent, deep-layer mean wind field and shear suggest more limited severe weather potential than further north. However, somewhat better boundary-layer moisture, including mid 60s F+ dew points, may contribute moderate CAPE ahead of southeastward advancing convective outflow. It appears possible that this could support re-intensification of convection that could become accompanied by sporadic damaging downbursts late Saturday afternoon into evening. ..Kerr.. 04/03/2026Read more
