There is a broad zone of severe thunderstorm potential this Saturday afternoon and evening from the High Plains into the Midwest and Ohio Valley. Within this larger area, several distinct corridors with varying severe weather threats are expected to develop.
The most widespread and concerning risk today will likely evolve along the Nebraska/Kansas border late this evening, where a cluster of severe thunderstorms with embedded supercells and pockets of significant straight-line winds may develop. High-based storms are expected to form off the higher terrain from east of Denver northward toward Sidney, Nebraska. An isolated tornado or two is possible with these initial storms before they likely develop a substantial cold pool and accelerate eastward.
As the storm cluster organizes and races east along the Interstate 70 and 80 corridors, increasingly favorable low-level wind shear may continue to support an embedded supercell or isolated tornado risk. Widespread wind gusts of 70 to 85 mph would not be surprising across parts of central and southern Nebraska into northern Kansas Saturday evening.
Farther east along an outflow-reinforced warm front, scattered supercells and messy storm clusters may develop across northeast Kansas, southeast Nebraska, and along the Iowa/Missouri border. A tornado or two is possible in this region, along with localized downburst winds over 65 mph and hail larger than 1.5 inches in diameter. Slow storm motions and clustered storm modes may also lead to pockets of excessive rainfall and flash flooding.
Farther south along the dryline, an isolated supercell or two may develop across southwest Kansas and the Oklahoma and Texas Panhandles, although uncertainty remains regarding whether a stout cap will prevent more robust storm development. Any sustained storm that forms in this environment could produce large hail exceeding 2 inches in diameter and perhaps a brief tornado.
Meanwhile, clusters of storms are already ongoing this morning across the Ohio Valley. Remnant outflow boundaries and localized circulations may interact with afternoon heating to reinvigorate thunderstorm activity later today. Organized severe weather appears less likely in this region, but a storm or two could still briefly intensify and produce a tornado, hail up to 1 inch in diameter, or localized 65 mph wind gusts.
Overall, the Nebraska/Kansas border region remains the primary area of concern this evening, where a potentially significant severe weather event focused on widespread damaging winds appears increasingly possible.